The inquiry into the Simshar tragedy is focusing on the sole survivor, Simon Bugeja, after investigations revealed discrepancies between his story and other evidence connected with the facts of the case, The Sunday Times has learnt.

Sources close to the inquiry said a number of questions had been raised in relation to Mr Bugeja's version of events.

Five people died during the ill-fated fishing trip last July, including Mr Bugeja's 11-year-old son Theo, his 61-year-old father Carmelo, Noel Carabott, 33, and Somali national Abdulrahman Abdala Gedi, 21.

Last week, Magistrate Joseph Apap Bologna was scheduled to interview Mr Bugeja for the second time since the inquiry began some six months ago. However, the fisherman asked for legal assistance from his lawyer, Robert Abela, and the questioning was postponed.

Dr Abela has now filed a request to be able to assist his client - which is not an automatic right under Maltese law - and the courts are expected to determine this application in the coming weeks.

Mr Bugeja's interviews had been put off for some weeks because of the psychological treatment he was receiving for trauma.

The fisherman, who owned the Simshar, had said he hung on to a makeshift raft for eight days before being spotted by a rescue party made up of fishermen. His son was with him throughout but slipped from his grasp just hours before the rescue. The boy's body was never found.

The tragedy - the worst fishing disaster in recent decades which had sent the village of Marsaxlokk into mourning - had sparked numerous conspiracy theories as to what could have happened.

Mr Bugeja had told rescuers that his vessel had sunk following an explosion on July 11, four days after it had set sail from Marsaxlokk. He was not able to explain what had caused the blast, however, fuelling rumours that the group could have been attacked by Sicilian fishermen or that they were carrying explosives to use for fishing.

Mr Bugeja never addressed these issues in public, referring to the ongoing inquiries. And although Fisheries Cooperative president Ray Bugeja, who is a distant relative, had confirmed that there had been a heated exchange between the Simshar crew and Sicilian fishermen weeks before the tragedy, he dismissed the theory of an attack.

Ray Bugeja had also said that although the Simshar was probably fishing illegally, there were no explosives on board.