A police team led by an Inspector has been assigned to Fonseka on the instructions of the police chief.
Fonseka, who was in jail serving several sentences, was freed late last month under a pardon granted by the President Mahinda Rajapaksa.
He was jailed by a military court and the high court for two separate offences. He is also attending court on another case.
Since his release, the former Army chief who was credited with leading the Army to victory over the LTTE has not taken any active political role.
He remains the leader of the opposition Democratic National Alliance (DNA).