"White widow" Briton in the spotlight in Kenyan mall attack

A Briton nicknamed the "White Widow" is in the spotlight after a Kenyan minister said a British woman was among the Islamist attackers who shot dead dozens of people at a Nairobi shopping mall.

Samantha Lewthwaite, a 29-year-old Muslim convert, was married to Germaine Lindsay, one of four suicide bombers who attacked the London transport network in July 2005, killing 52 people.

The mother-of-three has been on the run in East Africa for around two years and is wanted by Kenyan police for alleged involvement in a terror plot.

Kenyan officials have given contradictory statements about whether a British woman may have been involved in the attack on the Westgate mall which has left at least 62 people dead.

Foreign Minister Amina Mohamed told US public broadcaster PBS that a British woman was among those to blame, along with two or three American men.

"And she has, I think, done this many times before," Mohamed said, without identifying her.

But Kenyan Interior Minister Joseph Ole Lenku earlier denied that any of the insurgents were women, saying some male attackers "had dressed like women."

The British government refused to be drawn on suggestions one of its citizens was among the attackers.

The daughter of a British soldier, Lewthwaite professed herself appalled when her Jamaican-born husband detonated a rucksack full of explosives and blew himself up on a London Underground train on July 7, 2005, killing 26 people.

She was pregnant with their second child at the time.

"I totally condemn and am horrified by the atrocities which occurred in London," she said, describing Lindsay as "a good and loving husband and a brilliant father, who showed absolutely no sign of doing this atrocious crime".

Lewthwaite had met Lindsay in an Internet chat forum when she was 17, having converted to Islam two years earlier.

Described as a bubbly teenager, schoolfriends said she had an ordinary upbringing in the market town of Aylesbury, northwest of London.

"She was an average British, young ordinary girl," said Raj Khan, a local councillor who knew the family.

"She didn't have very good confidence," he added.

Little is known about what happened to Lewthwaite in the years after the London bombings.

Kenyan police released wanted notices saying she was travelling on a false South African passport under the name Natalie Faye Webb, accompanied by her three children, a girl and two boys.

The children would be now roughly aged between seven and 12.

South African authorities said they were carrying out a "thorough investigation" into the passport issue.

Media reports have linked her to plotting or masterminding attacks across the Horn of Africa, though with little evidence of her role.

Raffaello Pantucci, a terror expert at Britain's Royal United Services Institute, said Lewthwaite had acquired a "semi-mythical status".

"I don't think we've had any concrete evidence of her being involved in this incident," he said.

"But the fact of her being mentioned in this context is not surprising because of her connections."

Nairobi's Daily Nation newspaper quoted security sources saying that extremists on the Kenyan coast call her "Dada Muzungu" - "white sister" in Swahili - and that she had slipped through a Kenyan dragnet in Mombasa in January 2012, when forces raided villas where she was believed to have been hiding.

"Police have received hundreds of calls from people offering clues and have interviewed dozens who might have met her" in connection with the mall attack, Nairobi's The Standard newspaper said Tuesday.

But it added: "Very few individuals have ever testified to meeting Samantha face-to-face."

Lewthwaite has also been linked to Jermaine Grant, an alleged British Islamist currently on trial in Kenya's port city Mombasa for possessing explosives.

Rumours abound that Lewthwaite is behind the Twitter handle @MYC_Press -- Kenya's radical Muslim Youth Centre -- which regularly comments on Kenyan extremism, as well as entering into a war of words with rival Islamists.

American Islamist Omar Hammami -- who fought in Somalia but was killed by former Shehab comrades this month -- in April scoffed via Twitter that she was just "a girl in Kenya".

MYC_Press in turn replied: "Sam Lewthwaite thinks ur (you are) a irritating obnoxious contemptible little Muj (mujahedeen) PRAT."

MYC_Press -- which has been notably silent since the attack began on Saturday -- also told AFP in April that Lewthwaite had "returned to Luton", a town outside London and close to where she grew up.