The police were awaiting the results of special forensic tests to establish if a bomb at a Għargħur farm in May was planted there or was being assembled, sources close to the investigators said.

Kevin Ellul, 42, sustained serious injuries to his abdomen in the blast, which was heard over a wide area.

The sources told the Times of Malta that although the results of some forensic tests carried out on site were already known, the investigators were still waiting for the outcome of others in the hope of getting a better idea of whether Mr Ellul was the intended target of the bomb or the device detonated accidentally.

Two men, one of whom had been waiting for Mr Ellul outside the agricultural storeroom in Triq l-Isqof Gargallo, where the explosion went off, and another who fled the scene soon after the blast, have both been questioned by the police.

Mr Ellul too has been interviewed.

Very little is known of what emerged from the preliminary investigations. The sources said there were those who believed the explosion was linked to organised crime and drug trafficking, but declined to comment further.

The blast and the crater it caused indicated it was not as powerful as other explosions in recent months, including car bombs, the sources said. They added the power of the blast seemed to indicate the bomb had not been finished, however it was still too early to be certain.

Forensic samples lifted from the crime scene and crater and fragments of the explosive device recovered by experts were analysed, and tests continue in an attempt to get a better picture of what went on at the Għargħur farm. “This will hopefully give investigators more of a conclusive idea of what happened,” the sources said.