Siblings of Sion Grech, who was fatally stabbed in 2005, have filed a judicial protest against the State Advocate, Attorney General and Police Commissioner claiming a breach of constitutional rights.

In the protest they sue the state over the delay in investigating Grech's murder, and for failing to keep them updated about the prosecution of the suspects.

Grech, 20, was stabbed at least 17 times, and was found dead in a field near an HSBC branch in Marsa.

Eighteen years later, a nine-person jury cleared both Ismael Habesh and Faical Mohouachi of wilful homicide - a crime they had been charged with 10 years prior.

In the protest filed in the Civil Court, First Hall, on Friday, Rita Borg and Nadesh Said claim that the delayed investigation and prosecution shortcomings led to the acquittal of the accused.

This included six statements by one of the accused which had to be left out of the prosecution process following law amendments that were implemented after the murder. A "substantial amount" of documentation also had to be left out because of procedural errors, while several witnesses - including investigators - forgot particular details of the case. 

This all led to the state breaching human rights that protected life. The siblings insisted that the state was obliged to immediately investigate murder.

Additionally, the siblings lament, they were not kept updated about the investigation into the murder of Grech, and the prosecution of the suspects. This too breached the European Convention on Human Rights. 

The siblings called for financial compensation in view of such breaches and warned, in the protest, that they were willing to take further action if no compensation was forthcoming. 

Grech used the pronouns she/her. Given that she was murdered years before the Gender Identity, Gender Expression and Sex Characteristics Act of 2015, she is listed in legal documents as a male named Simon. Previous court reports stated that she was also known as Simone. 

Lawyers Roberto Montalto, Evelyn Borg Costanzi and Matthew Cutajar signed the protest for Borg and Said.