Colombo Chief Magistrate Asanga S. Bodaragama ordered that alleged underworld operative "Commando Salinda" be remanded until July 16.
The order was issued after officers of the Criminal Investigation Department (CID) submitted a further report to the Colombo Magistrate's Court.
The suspect, who is currently being questioned while in CID custody, was produced before the court via Zoom.
"Commando Salinda" has been named as a suspect in the fatal shooting of alleged underworld figure "Ganemulle Sanjeewa," who was gunned down while inside a courthouse earlier this year.
Further investigations are being carried out by the CID.