Mr Asbo the swan 'worse each year', Cambridge rower claims

A rowing organisation says the swan's behaviour is becoming increasingly dangerous

An aggressive swan nicknamed Mr Asbo must be removed from a river before he kills a young sculler, Cambridgeshire Rowing Association's chief has said.

Bill Key, president of the association, said the swan, which has attacked River Cam rowers several times, could smother a young sculler.

River managers had applied for a licence to move the bird and his mate, for the safety of river users.

However, now the mating season has started, it is illegal to move them.

The Conservators of the River Cam said earlier this year they had met the criteria laid down by Natural England for permission to move the swans.

But the application was deferred when inspectors were unable to determine whether the pair had started mating.

'Impressive lad'

Natural England said it would reassess the situation in September.

Mr Key said he was becoming increasingly concerned for the safety of river users.

"I have been attacked on a number of occasions but I can look after myself.

"There are a lot of young scullers on the river who have to hold on to both blades and have no means of defending themselves," he said.

"The bird could quite easily knock one of them into the river and then smother them while they're under the water."

Dr Philippa Noon, of the conservators, said she was disappointed her organisation had been unable to secure the birds' move.

She said river managers recognised rowers' concerns.

"I do actually think the bird has learned some new techniques this year," she said.

"He's quite an impressive lad and can now get on board some boats.

"We were cleaning up the river recently and he made a beeline for our boat. He kept up with us for about a quarter of a mile.

"You could see his muscles bulging and he really was very determined."

Until the birds can be removed, Natural England has suggested "mitigation methods" including keeping the swan family in a safe enclosure during river events and continuing to monitor Mr Asbo's behaviour.