The Libyan woman who burst into a Tripoli hotel to tell western reporters she had been raped by Muammar Gaddafi's militiamen is now facing criminal charges herself, a government spokesman said.

Iman al-Obeidi was detained on Saturday after she entered the capital's Rixos al-Nasr hotel and told journalists she had been beaten and repeatedly raped by 15 troops at a checkpoint.

With TV cameras rolling, she was tackled by waitresses, security men and government minders and dragged away struggling. At least two journalists were beaten or punched in the fracas.

Spokesman Mussa Ibrahim said charges had been brought against her by some of the militiamen she had accused. "It's a legal case," Ibrahim told reporters. "The boys she accused of rape are making a case against her because it's a grave offence to accuse someone of a sexual crime."

It was unclear whether she is still in custody. Ibrahim initially said she was free and safe but then seemed to qualify this, saying he was unsure whether she was currently under investigation.

He said later that Obeidi was refusing to undergo a medical examination and that this was making it difficult to investigate her complaint. Lawyers for the men she alleges raped her were using her refusal to question the truth of her story, he added.

Obeidi's case was raised in London by a leading member of Libya's Transitional National Council. Guma El-Gamaty, the council's UK co-ordinator, told a press conference at the Foreign Office that Obeidi had been raped by a cousin of Muammar Gaddafi.

He said: "We think it is genuine case of kidnapping and raping.

"We think that this is just the tip of the iceberg of the sort of things the security services and security people carry out in Libya. It is one way of terrorising the population … we think the perpetrator in that particular case is somebody who is high- profile and very close to Gaddafi himself – in fact, a cousin of Gaddafi."

Previous statements in Tripoli about Obeidi have proved to be incorrect. After the hotel incident Ibrahim, the government spokesman, said she was a prostitute who had been released and was staying with a sister in Tripoli.

But in an interview with al-Jazeera Arabic TV, broadcast on Monday, Obeidi's parents said she was being held hostage at Gaddafi's Bab al-Aziziya compound in the capital. The mother said she received a phone call on Monday from an unidentified caller, purportedly from the Gaddafi camp, telling her Obeidi was at the compound and asking her to instruct her daughter to change the rape claim in return for freedom and other benefits.

"Whatever you ask for, you will get: build a new house or get the money," the mother said the caller offered.

Ibrahim previously described Obeidi as drunk and mentally disturbed, but until Tuesday he had said her only offence was entering the Tripoli compound, where large numbers of foreign journalists covering the Libyan crisis are staying at a luxury hotel-cum-media centre.

Ibrahim, a natty dresser who was recently awarded a doctorate in mass communications from Royal Holloway College, London, is articulate in defending Libya but often flummoxed by questions and complaints about the severe restrictions imposed on journalists working here.

On Tuesday, he expressed frustration at repeated questions about the Obeidi case when, as he put it, Libya is facing daily air strikes in which civilians are being killed and injured.

The story has sparked extraordinary international interest. Messages of support flooded the Free Iman al-Obeidi Facebook group in English, which had been "liked" by more than 2,300 people.

"I admire her for her bravery and courage," said Amir Shakoor in a post. "Her sacrifice will not be wasted and she'll stay symbol of freedom for good. We all pray that she is safe and sound."