Animal rescue teams will not step in to save Simon the seal which has become trapped in a freshwater river.

He swum up the River Medway and through Allington lock where the 19km freshwater river reaches its tidal limit.

The lock was open due to high spring tides but has now been shut, effectively trapping the coastal animal up-river. Since then Simon has continued up through Maidstone town centre to East Farleigh.

Representatives from the RSPCA and British Divers Marine Life Rescue say they do not plan to remove Simon who, they insist, remains “happy” where he is, catching fish.

However Mark Stevens, director of BDMLR admitted seals normally live in colonies and that Simon was stuck by himself unless he worked out how to operate the lock system.

Mr Stevens said: “All the time it’s happy and not being harassed we won’t move it.”

And he admitted there wasn’t much chance of Simon meeting a female companion in East Farleigh, adding: “They don’t all need to breed, just like not all humans need to breed.”

BDMLR chairman Alan Knight said seals had been known to upset fishermen in the past.

He said: “At Sturry, a seal had started eating fish which the fishermen wanted. They were going to shoot the seal so we put a guard there overnight. The guard got beaten up.

“In Scotland they were going to shoot a seal that was eating salmon but we said 'why don’t you make it an honorary club member’. They did and got loads of good press.”

And he said moving Simon could prove tricky as seals are notoriously difficult to trap.

“We could spend days trying to trap a healthy animal; it’s a lot of spent energy,” he said, adding: “I’m sure he’ll turn round and work his way back sooner or later.”