The Criminal Investigations Department (CID) has been entrusted with the task of handling investigations into the brawls in Parliament earlier this month.
The CID investigation will continue, in addition to the parliamentary investigation into the same matter.
The Police investigation will look into the parties that are responsible for bringing knives and chilli powder into the House.
Nearly 10 police officers received treatment following the brawl that took place in Parliament during the second no-confidence motion against former President Mahinda Rajapaksa in Parliament.