Police investigations into clashes between Maltese tuna fishermen and environmentalists were still under way and “no significant developments” had been reported since the June incidents.

Members of the police Administrative Law Enforcement unit, which is leading the investigations, have spoken to Italian fishermen through Interpol. The police now have to speak to other potential witnesses, including their Libyan counterparts and French fishermen, according sources said.

Two of the June clashes involved the Sea Shepherd Conservation Society, an international non-profit, marine wildlife conservation organisation. In one of them, two fishermen were injured and hundreds of fish were freed off the coast of Tripoli, Libya. In the second clash, fishermen rallied to defend their tuna pens and the Libyan navy intervened to ward off what might have been another ugly incident.

Commenting after the Sea Shepherd incidents, marine consultant Reuben Lanfranco said the actions of the society could be described as an act of piracy under the UN Convention on the Law of the Sea.

Paul Watson, who headed the society’s anti-tuna fishing operation in the Mediterranean, was recently placed on the international wanted list by the Japanese coastguard over similar clashes with whale fishermen.

In an earlier clash in June involving Greenpeace International, no one was injured and no tuna were released although the Armed Forces of Malta were called in to protect a pen.