A July 7 bomber's widow, suspected of being part of a terror cell, has fled Kenya for Somalia, a top police official has said.
Samantha Lewthwaite, 28, arrived in the East African country last year as part of a group which allegedly planned to bomb the region's coast over Christmas and New Year.
But the mother-of-three, who is said to have been in charge of the plot's finances, is now understood to have crossed the border into Somalia, the Kenyan police officer confirmed.
Lewthwaite was married to King's Cross suicide bomber Jermaine Lindsay, 19, who carried out the most deadly of the July 7 attacks, killing 26 people.
Last week, her father Andy, 56, pleaded for his daughter to contact her family and insisted she would not be embroiled in terrorist activity.
Lewthwaite, originally from Aylesbury, Buckinghamshire, became the focus of police attention after it emerged Kenyan detectives were hunting a woman using several identifies - including hers.
Lewthwaite told The Sun: "I just wish she would get in touch with us."
The builder said he had not seen his daughter for months and that the family had not heard from her for some time.
"Samantha would not be involved in anything to do with terrorism," he said.
"She was badly affected by what happened before and would have nothing to do with it. I am sure of that."
Kenyan officers believe Lewthwaite - who is reportedly travelling with her children - was most recently using the name Natalie Faye Webb and carrying a forged South African passport.
She is believed to have evaded capture when authorities carried out a raid on a group suspected of plotting a terror attack in the coastal town of Mombasa.
Scotland Yard said it had sent a team of officers to Kenya to assist authorities with a terror-related incident.
Lewthwaite converted to Islam at the age of 15 and married Lindsay in 2002 before he blew himself up in July 2005.