Investigations into last week's Marsa car bomb have turned up few leads on who could have wanted to kill a man by planting a bomb underneath his van, and surveillance footage has not shown anyone fiddling with the vehicle.

Sources close to the investigation said investigators were not ruling out anything but looking into every detail, including 35-year-old Josef Cassar’s business links and possible connections to previous bombings.

The explosive device had sprayed shrapnel, including screws and ball bearings, across the cabin of Mr Cassar’s Ford Transit van, ripping through the bones and tissue of both his legs.

Investigators have since also excluded the possibility that the bomb was planted inside the vehicle, because the blast moved in rather than outwards, indicating it was  placed underneath the car.

He provided little help in terms of naming those who could have wanted to harm him

Mr Cassar, the sole director of S&T Services Ltd, a haulage company based in Marsa, is no longer in intensive care, though he is still receiving treatment at Mater Dei Hospital. He has been questioned by investigating officers and also by the inquiring magistrate and court-appointed experts.

The sources said Mr Cassar provided investigators with very little help in terms of who could have been behind the attack and names of people he suspected could have wanted to harm him.

Hours of closed circuit camera surveillance footage was also viewed but this also proved useless to investigators, who are hoping technology will help them track the mobile phone used to spark the explosion remotely. Tracking a mobile call was complicated but the process was well under way, the sources said.

The bomb exploded Aldo Moro Street, Marsa at about 6.15pm on September 26. It was the second such attack in the space of nine months. In January, Martin Cachia, 56, was killed when a bomb went off in his car.