Most of the prospective candidates have been biding their time before declaring their intention to join the race for the presidency, in which the incumbent, the US-backed Hamid Karzai, is clear favourite. However, one candidate has already made her intentions clear. Posters bearing the photograph and a brief biography of Dr Massouda Jalal can be seen around the capital: there is even one at the guardpost outside the city’s military hospital. The 41-year-old, who visits Britain this week as a guest of the Foreign Office, teaches paediatric medicine at Kabul University. Her candidacy, she says, is a challenge to the old order and to all forms of discrimination.

Sitting in the first-floor flat she shares with her husband and three young children on the outskirts of Kabul, Jalal says she believes there are a number of reasons why the country needs a change in its style of leadership. “One of the main issues we have to fight is corruption and I do not believe that the interim government has been able to deal with this,” she says. “I also believe that a woman leader would be better at bridging the gap between Afghanistan and the international community.” Her candidacy was publicly denounced at a meeting by one former mujahideen leader, Ayatollah Mohseni. “He called a woman’s candidacy for the presidency of Afghanistan illegal, but right away 200 or 300 people stood up and objected  and left in protest,” says Jalal, whose campaign is run on a shoestring.

Although violent attacks on election officials are an almost daily occurence, Jalal says she is determined not to be intimidated. “I have no security support from the government. It is not interested in my health or life. But I have felt no danger up to now. I have no armed guard and, as you can see, my door is open.”

She says men and women number equally among her supporters, and that her family is proud that she is attempting to become the country’s first female leader. Although there are still many barriers for women in Afghanistan which she would want her presidency to address, “there are some changes. Women can move around freely, at least during the day, and there are more job opportunities. But most of them still have no personal property and, if they have the courage to stand as a candidate, there is no attention paid.”

Carol Le Duc, an Englishwoman who has lived and worked in Afghanistan for the past 14 years, says that there have been significant political developments since the fall of the Taliban in 2001. If the new constitution works as intended, she says, women will make up 25% of the government after the parliamentary elections, postponed until next April following the recent violence; a quarter of seats are reserved for women. This is roughly twice the percentage in the United States, she notes.

“But civil rights for women?” she says. “Light years off.” The major problems for women remain a lack of opportunity and fear for their personal safety at home, says Le Duc. She points out that the mistreatment of women flourished under the mujahideen.

Now, she says, women who work can still be dismissed by men as “whores”. “Women say that men don’t know how to behave towards them,” says Le Duc. “Not a week goes by without a report of a gang rape by a warlord, or a woman beaten almost to death by her husband. Women are still valued for their reproductive rather than their productive role.”

However, more women have now moved into positions of authority in non-governmental organisations. They have ensured that the issue of forced and underage marriage is back on the political agenda, and it could become a key election issue. The large numbers of women who attempt suicide by burning themselves with cooking oil has highlighted the issue.

“What does the high level of self-immolation in Afghanistan mean?” asks Horia Mosadiq, a 31-year-old journalist and human rights activist. “What can be so bad that it makes you want to kill yourself? In [the province of] Herat, there were 183 cases of self-immolation last year and 26 women died.” The worst mistreatment of women remains in forced and child marriages, says Mosadiq, sometimes between very elderly men and girls as young as nine or 10. “This is not part of the Islamic principle at all,” she says. “The Holy Prophet said that a couple should be equal  in age, education and wealth. The people who carry out these marriages are not obeying Islamic rules.”

Ahmana Afzali of the Independent Human Rights Commission agrees that Islamic law has been wrongly used to justify discrimination against women. A former exile in Iran, she returned to Kabul to teach biology at the university. “We would like to see women have real equal rights, not just in theory,” she says. “The position of women has improved in the past few years but not enough. Of course, under the Taliban all of the human rights of women were ignored. But we have to change attitudes  many women still say, ‘We are women so we cannot go out.’ We have to change that.” Two other major election issues, as in Britain, will be education and health, both areas that have particular significance for women in Afghanistan. There are now incentives for families in the more conservative provincial areas to put their daughters into the educational system. The UN’s World Food Programme offers girls who go to school a monthly food supply for six people in the form of rice, cooking oil and so on.

“In our country, we have cultural restrictions  they do not like girls to attend school,” says Basir Qreshi, the programme assistant in Jalalabad. “There is a gender gap, but the outcome has been positive. Before this started in 2002 there were a million girls in school; now there are 2.5 million.” The UN’s Food for Education programme, aimed at widows, women with disabilities and returning refugees, is also using food to encourage women into the educational system. Women who take courses in literacy, embroidery, beading, tailoring and carpet-weaving will receive food supplies for themselves and their families for the duration of their courses.

Health remains another major issue, not least because women feel unable to discuss their problems even with their husband. “One woman dies every 20 minutes in Afghanistan as a result of complications in pregnancy,” says Eddie Carwardine, a spokesman of Unicef. The province of Badakhshan currently has the world’s highest maternal mortality rate: 6,500 per 100,000 women. This compares with 13 per 100,000 in the UK.

“The educated girl tends to grow up to be a healthier woman, but here you are looking at a country where 70% are illiterate,” says Carwardine. He adds that, despite stereotypical notions of Afghan manhood, most men express great appreciation for the healthcare their wives are now entitled to. “Many of the men will tell you how frightened they were [when their wives were ill during pregancy].” Imams and mullahs also encourage women to take advantage of the health programmes, he says, again defying stereotype.

Full-scale election campaigning has yet to get under way in Afghanistan, not least because of the attendant violence and fear. Clearly, the votes of more than two million women will be eagerly courted by all sides. Le Duc says that women could play a key part in the political life of the country if they are allowed to, and adds that it is a western misconception that associates the burka with submissiveness. “These are not shrinking violets, they are tough women.”

At the heart of their investigation is a former American special forces soldier, Jonathan Keith “Jack” Idema, who is alleged to have run the private jail and was being questioned last night.

Mr Idema, who is said to be always heavily armed, is far from the only ex-military man to be making a living in Kabul, which has an atmosphere redolent of The Third Man, Graham Greene’s thriller about postwar Vienna.

Many of the private security guards attached to embassies and commercial companies have military histories, either real or imagined. Typically, they can be seen in dark glasses and camouflage gear, sub-machine guns slung over their shoulders as they ride through the city. They are often to be seen at the Mustafa hotel, one of the few bars that sell alcohol to ex-pats, who gather for the hotel’s popular roof-top barbecues.

Mr Idema, it emerged yesterday, has a colourful past. A volatile former Green Beret with a criminal record in the US, he describes himself as a security adviser. He also claims that he is the person on whom George Clooney’s part in the Hollywood film The Peacemaker was based.

While there has been no official explanation of what sort of operation he was running, there are large rewards on offer for the capture of al-Qaida members in Afghanistan, which has led to a boom in the private security business.

The biggest reward of all  $25m  remains on offer for information leading to the capture of Osama bin Laden.

Mr Idema knows all about him, having collaborated with Robin Moore, the author of the book The Hunt for Bin Laden, a gung-ho account, published last year, of the so-far unsuccessful pursuit of the al-Qaida leader.

Officials revealed that when Mr Idema and two other Americans were arrested, they were all armed and dressed in US military-style uniforms.

An Afghan official told the Associated Press that the prisoners were “hanging upside down” in the house in the quiet suburb of Kart-i-Parwen, and had been beaten.

The American military appear to have suspected that Mr Idema was involved in something nefarious. Since last week, they have been quietly briefing journalists about him, stressing that he has no connection with the US forces.

And following the arrest, a public statement was issued by the US military saying that he had “allegedly represented himself as an American government and/or military official  The public should be aware that Idema does not represent the American government and we do not employ him.”

Mr Idema has a chequered history not untypical of some of the ex-military personnel who have been drawn to Kabul. Although the US military authorities would not confirm his record yesterday, he is said to have been a member of the special forces between 1975 and 1992.

After leaving the forces, he ran a military equipment firm in the US.

He was convicted of wire fraud and other offences in connection with that business in the 90s.

One rightwing news website in the US suggests that he was only charged after he refused to cooperate with the FBI and the CIA over information which he claimed he had about weapons-grade nuclear material being sold in Russia to foreign terrorist groups.

This information, gathered when he was in Lithuania, is the source of a legal action that Mr Idema launched against Steven Spielberg’s film company DreamWorks SKG.

In 2000, he issued a writ against DreamWorks, claiming its 1997 film The Peacemaker, which starred George Clooney and Nicole Kidman, was based on his story.

The film is about a maverick American colonel, played by Clooney, who tracks down a Russian nuclear smuggling team.

He claimed damages of $130m. The case is ongoing.

In the meantime, he had become something of a media security pundit, popping up on television programmes to comment on security matters.

During the war in Afghanistan in 2001, Mr Idema and a number of other former US military members linked up with the Northern Alliance rebel group, who were fighting the Taliban. He offered his services to the media and appeared on American television news programmes after having supposedly found al-Qaida training camp footage in Kabul.

When Fox News showed the footage, Mr Idema launched another civil action, seeking $2m damages for supposedly showing the footage without his permission.

He also threatened to punch Geraldo Rivera, the controversial Fox News commentator, who, Mr Idema claimed, had messed up the operations of the Northern Alliance by irresponsible reporting.

Mr Idema, who has a reputation in Kabul for volatility, is also the source of much internet gossip on sites used by ex-members of the US special forces, not all of whom would describe themselves as admirers.

Now Mr Idema remains in the custody of Afghanistan’s intelligence officials. In a country where the legal framework barely exists, his stay could be even longer than that of his detainees.