Businessman Joe Gaffarena was released from arrest yesterday after 48 hours and two of his sons were questioned as part of “a broad” police investigation.

He was arrested on Sunday afternoon and released as the mandatory 48-hour period drew near. Sources said the arrests followed an investigation, the nature of which is not known, that has been going on for the past few weeks.

At least seven more people were questioned by the police and more are expected to be called in.

The Gaffarena family featured prominently in an inquiry last July by retired judge Michael Mallia into the behaviour of former police inspector Daniel Zammit in the procedures following the Qormi murder of Neville Baldacchino in December 2008.

More people are now expected to be called in

Steve Caruana, husband of Mr Gaffarena’s daughter, Romina, is being accused of Mr Baldacchino’s murder. Mr Zammit was prosecuting officer until he retired last April.

The Mallia inquiry found that six months after Mr Baldacchino’s murder, Mr Zammit and his brother, Roderick, a serving police officer, bought land in Baħrija.

The seller, Alfred Chircop, was the uncle of the wife of Mr Gaffarena’s son. The land was sold to Mr Chircop by Alfaclass Developers Ltd, whose shareholders included members of the Gaffarena family as well as Romina.

Judge Mallia expressed his concerns that the police murder investigation had been “compromised” by the Gaffarena family, which arrived at the scene of the crime before the police. Moreover, the extraction of data from mobile phones by the police took “an inordinately long time”.

The court case has been stalled since January 2010 following the prosecution’s request for swabs to be taken from Romina Caruana.