A Somali-born man who escaped from special police surveillance by disguising himself in a burqa has exposed shortcomings in the way Britain handles some terrorism suspects, prompting an embarrassed government to announce a review.
Mohammed Ahmed Mohamed, who is suspected of having links with Somali Islamist group al-Shabab, gave authorities the slip last Friday by donning the full-length woman's religious garment while attending prayers at a London mosque.
It was the second time a terrorism suspect had absconded in the past 10 months and the main opposition Labour Party blamed new government rules it said made it easier for such people to evade surveillance.
"There will of course be a review ... and any lessons that need to be learned will be," Theresa May, the interior minister, told parliament.
"A number of operational issues will be looked at," she said.
Mohamed, a British citizen, was subject to special control measures used in a small number of serious cases where it is not possible to prosecute or deport someone suspected of terrorism-related activity due to a lack of usable evidence.
That meant he had to wear an electronic tag so that the authorities could track his whereabouts and was subject to other forms of surveillance as well as restrictions such as curfews and regular home searches.
May said Mohamed, 27, had been subject to such measures to stop him travelling abroad "to support terrorism".
Local media have reported that he trained and fought with al-Shabab. May neither confirmed nor denied those reports when lawmakers raised them.
Police have launched a manhunt, though the government has said he does not pose "a direct threat" to the public, while warning anyone who sees him not to approach him.
May rejected calls from some lawmakers in her ruling Conservative party to ban the burqa because of the case, saying she believed women should have the right to wear what they want.
Labour said any review would have to urgently answer questions about how Mohamed was able to abscond.
"This is extremely serious," said Yvette Cooper, Labour's spokeswoman for justice matters.
"Mohammed Ahmed Mohamed is now the second terror suspect to abscond from a TPIM (terror prevention and investigation measure) in London in the space of 10 months. That does raise serious questions about the nature of the controls involved."