Persons are sent to prison on fabricated drug charges in order to extort money from them, he has told the media.
Innocent people are taken to police stations, hung from their hands, their heads inserted into polythene bags and chilli powder put into their eyes, he said.
He also accused police of killing persons in its custody and described it as being completely inhuman.
Continuation of Gotabhaya Rajapaksa era
Fonseka went onto say that such human rights violations continued from the period of Gotabhaya Rajapaksa to the present administration.
He said however, the police should be given the task of curbing the drugs menace, and objected to a presidential decision to deploy the Army for the purpose.
In a report submitted by the Sri Lanka Human Rights Commission to the United Nations in March 2017, it was alleged the torture of arrested persons was widespread.
The ITJP, led by Yasmin Sooka has said that it has listed more than 70 persons who had managed to escape after being tortured under the present regime.
The UK-based Freedom from Torture says Sri Lanka is the top source for freedom from torture referrals.