Kenya police believe the suspect in last week's killing of a British soldier in the U.K. had earlier associated with a radical Kenyan imam who tried to help him join an al-Qaida-linked group in neighboring Somalia.

A senior police official said Tuesday they believe Muslim cleric Aboud Rogo Mohammed, who has since been killed, helped British citizen Michael Adebolajo in his attempt to travel to Somalia to wage jihad against the country's U.N.-backed government.

Adebolajo was arrested with five other young men in November 2010 on a Kenyan island near Somalia, then set free. Adebolajo and another man are suspected of killing a British soldier who was run over with a car and then stabbed in London.