It comes at a time Minister Kumaranatunga is poised to support Common Opposition candidate Maithripala Sirisena.
According to close aides of Kumaranatunga, the growing suspicion of the Minister supporting Maithripala was what led to the removal of his driver.
Minister Kumaranatunga was a cousin of the assassinated actor and politician Vijaya Kumaranatunga who was the husband of former President Chandrika Bandaranaike Kumaranatunga.