The heirs of murdered taxi driver Matthew Zahra have filed a judicial letter asking the Police Commissioner to explain how a €25,000 gold chain he was wearing when murdered went missing from the police strong room.

Krystal Grixti, Mr Zahra's partner with whom she had three children, also called on the commissioner for compensation for the necklace that was stolen as a result of negligence in the way evidence was stored.

In the judicial letter, filed in the First Hall of the Civil Court, Ms Grixti - also on behalf of her three children - said that when her partner was murdered in 2012 she ended up having to cope alone financially. The disappearance of the chain was of serious prejudice to her.

Apart from the financial worth of the chain, police had also allowed a crucial piece of evidence in the murder of her partner to be stolen.

Mr Zahra’s family is seeking explanations about the jewellery, which police say was deposited in the strongroom where exhibits are held on August 25, 2012, and could not be traced when they went to retrieve it on May 16, 2013.

Police Inspector Fabian Fleri had testified that no surveillance cameras were installed at the police headquarters’ strongroom. Although cameras monitored other areas of the depot in Floriana, there were none outside the quartermaster’s stores at the time the €25,000 gold choker vanished.

Insp. Fleri was testifying, in November last year, in the compilation of evidence against Jason Galea, 39, of Marsa and Ronald Urry, 49, of Paola, who deny murdering Mr Zahra in August 2012.

Mr Zahra’s remains were found buried in a field in Qajjenza last year. Alfredo Attard testified in court that before burying the victim and covering his body with soil, Mr Urry took a gold necklace from around Mr Zahra’s neck but Mr Galea asked him to put it back.

The necklace was eventually found on someone who claimed to have bought it from Mr Galea.

Lawyer Stefano Filletti signed the letter.