Prime Minister Joseph Muscat on Tuesday avoided a question on why he had continued to back his former chief of staff Keith Schembri to the bitter end.

"That may be something that I will have the time to write and speak about in the near future," Dr Muscat said when reporters intercepted him as he walked into Auberge de Castille.

Mr Schembri resigned two weeks ago after the middleman in the Daphne Caruana Galizia murder plot, Melvin Theuma, mentioned his name to the police.

He was arrested by the police and released without charge.

He was also re-arrested and released over the weekend after being questioned about a phantom job which the middleman claimed he was given in the public sector by Mr Schembri.

Mr Schembri on Monday dropped two libel suits against Daphne Caruana Galizia.

He has not been seen in public since his resignation but Neville Gafa' (the prime minister's envoy to Libya) has been repeatedly seen entering his villa in Mellieħa.

A car has also been seen parked outside the villa and then outside the Auberge de Castille.