Former OPM chief of staff Keith Schembri has been released by the police this evening, the police said.
Over the past day, Schembri was investigated in connection with allegations made against him in relation to the murder of Daphne Caruana Galizia.
At this stage, the police said, it does not deem it necessary for Schembri to remain under arrest.
Schembri resigned from the post of OPM chief of staff last Tuesday.
Matthew Caruana Galizia, the son of the slain journalist, said that despite the "damning evidence" that exists, the police released Schembri.