Melvin Theuma was on Wednesday evening called in by police for questioning over his claim in court that he had a contract of employment with a government company.

The alleged middleman in the Daphne Caruana Galizia murder plot told a court  that he was given a job in May after meeting with the Prime Minister's chief of staff Keith Schembri.

Sources close to the investigations said police are probing the job he was given on May 1 2017, the same day that the election was announced.

Investigators are believed to be verifying certain details about the job which were  mentioned in the infamous letter sent by Mr Theuma, to Yorgen Fenech, the alleged mastermind of the October 2017 assassination.

Sources said searches were conducted at JobsPlus offices in Malta and Gozo. 

In his testimony, Mr Theuma described how Mr Fenech had told him he was to receive a call from Sandro Craus, the Head of Customer Care at the Office of the Prime Minister. 

Mr Craus called and invited him for a meeting with Mr Schembri, who took him on a tour of Castille and ordered him coffee. Afterwards, Mr Craus informed Mr Theuma of a job he was being given with "a ministry opposite the old theatre".

Mr Theuma said he never reported for work but still received three or four salary cheques and that he stopped being paid after the June election was over.

Sources close to the police said investigators are probing the way Public Service Commission rules were bypassed in this case. They suspect forgery of some sorts, including in time-in time-out sheets. 

The sources said Mr Craus is a person of interest in this case and is also expected to be called in for questioning.