Kenya is investigating reports that British terror suspect Samantha Lewthwaite – known as the “White Widow” – has been sighted in the country.
Reports say an unknown woman, possibly Ms Lewthwaite, was given a police escort to visit a Kenyan army base in Somalia before disappearing.
She is accused of links to Somali Islamist group al-Shabab, which has attacked Kenya several times.
Ms Lewthwaite’s husband died in a 2005 suicide attack.
Her husband Germaine Lindsay was one of the four bombers who carried out the 7 July bombings in London that year in which 52 people were killed and hundreds more injured.
Kenyan police officers in the coastal town of Lamu provided an armed escort to an unknown white woman who disappeared after her attempts to enter Somalia were blocked by immigration officials.
She had said she was working for a United Nations agency and wanted to visit a camp belonging to the Kenya Defence Forces in Somalia, police say.
But upon reaching the Kiunga border post, customs officials questioned her identity and refused to grant her permission to enter Somalia.
Kenyan Army spokesman Willy Wesonga has confirmed that a team of detectives is investigating whether the woman was Ms Lewthwaite and, if it was her, why she intended to visit the Kenyan army camp.
After last year’s attack on the Westgate shopping centre in Nairobi, Kenya sought an international warrant for her arrest.
She was reported to have been linked to the attack but this was not mentioned on the warrant.