A Greenpeace activist whose leg was punctured right through with a grappling hook during a standoff with fishermen on a French boat yesterday vowed from his hospital bed in Malta to return to protest against tuna fishing.

"I will be back, although maybe not this year," Londoner Frank Hewetson told The Sunday Times.

The 45-year-old father-of-two underwent surgery late on Friday after a grappling hook used by fishermen to grab tuna from pens passed straight through his left leg as he was trying to free tuna from a commercial fishing net some 60 miles south of Malta.

On Friday, Greenpeace activists on board the Rainbow Warrior and the Arctic Sunrise found around five purse seiners - boats which drag large nets used in tuna fishing - together with some 10 support boats. The activists released inflatable boats and attempted to weigh down the side of one net with sandbags, allowing the tuna to escape "without damaging it or cutting it," Mr Hewetson said.

"However, the fishermen were extremely angry and attacked us for the following 15 minutes, beating us with sticks, puncturing our boats, driving over them," he said, adding that two of Greenpeace's inflatable boats were sunk during the incident.

According to Greenpeace International campaigner Oliver Knowles, the fishermen also fired rocket flares at a helicopter. A video released by the organisation shows fishermen ramming Greenpeace boats with theirs and hitting activists with metal gaffs.

Speaking from his bed at a private hospital, just hours after an operation, Mr Hewetson, who has been a Greenpeace activist for 20 years, said the fishermen either threw or fired a grappling hook at the inflatable boat he was on.

"They pulled it tight and it went straight through my left leg," he said, adding that the points were around 10 to 12 inches long, and stuck some five inches out of his leg.

"I was then dragged down the deck until my leg got stuck at the front of the boat. They then towed our boat using my leg as an anchor."

Asked whether the fishermen realised he had been caught by the hook, Mr Hewetson said: "They did, they saw it because I have to admit I did scream like an eight-year-old girl. They looked down and kept on pulling."

Eventually he grabbed the hook and pulled it out of his leg, throwing it into the water. But the fishermen threw another hook, catching the back of the boat. "I presume they were trying to pull our boat and sink it."

Although injured and bleeding profusely, Mr Hewetson managed to get to the back of the boat and cut the rope and signalled to the other activists to leave.

"It just got too violent and crazy. I think they are desperate people with a desperate fishing industry that they and others have driven to the point of extinction. I think they have only themselves to blame for mismanaging such an important resource."

Mr Hewetson was flown over to Malta on Friday afternoon and operated on in the evening.

"There's a hole all the way through, between my shin bone and calf muscle around six inches up from my ankle."

Doctors had to clean the hole because of risk of infection. Mr Hewetson is now on strong painkillers and intravenous antibiotics, and is expected to be in hospital for another few days.

Asked whether Greenpeace was planning to take legal action against the fishermen, Mr Hewetson said that could be difficult since the incident happened in international waters. However, it was going to file a protest with the French government and the French fishing industry.

AFP yesterday reported that France's national fisheries body backed the fishermen, saying they "were attacked by helmeted Greenpeace activists, equipped for and engaged in a violent operation - the destruction of a work tool".

In a statement, the Federation of Maltese Aquaculture Producers condemned the use of violence but said the incident occurred because the activists intervened in a legitimate fishing operation.

The fishermen, it said, had done nothing to provoke attention from the activists except by carrying out their legitimate business and the activists' efforts were violent and illegal.

"The activists should not have expected the fishermen not to resist the attack; they sought confrontation and got the confrontation they wanted."