A British woman is thought to be among militants who killed at least 62 people at a Kenyan shopping centre, Amina Mohamed, the country's foreign minister has said.

Her comments have fuelled speculation about the possible involvement of British terror suspect Samantha Lewthwaite - the widow of 7 July suicide bomber Germaine Lindsay.

BBC journalist Peter Taylor told the Today programme's Evan Davis that it was thought that "Samantha Lewthwaite, the so-called white widow... became involved in al-Shebab in Kenya."

He had been in Kenya until just before the attack making a Panorama programme and collecting information on the British connections to al-Shabab.

First broadcast on BBC Radio 4's Today programme on Tuesday 24 September 2013.