Workers at a wildlife centre have described their shock at discovering the theft of some of the rarest birds in the world -- and the senseless killing of others.

A breeding programme for the endangered white-winged ducks from Sumatra has been dealt a heavy blow following the theft of a pair of the species from the Washington Wetlands Centre.

Warden Darren Grieves arrived work on Tuesday to discover intruders had broken through chain link fence.

As well as the white-winged ducks, two Phillipine ducks the sized of a mallard and one marbled teal were stolen.

But worse was to follow, when several bodies were discovered in the same area.

Andrew Donnison, manager of the centre which specialises in breeding endangered species, said last night: "It is unbelievable that people can carry out such sick acts of vandalism and cruelty.

"Whatever the reason for the thefts, there can be no reason or excuse for the cruel way these harmless ducks have been killed.

"One of the birds was headless and the others we believe had been hit against something _ although we are awaiting a full post mortem on them."

Among the birds found killed was the rare and beautiful Mandarin Duck, a favourite bird of many visitors to the Washington Wetlands Centre. Mr Donnison said: "This is the first such incident at the centre in over ten years.

"Staff are particularly disappointed given the record number of people who visited the centre in 2003 to enjoy these birds.

"The white-winged ducks are so rare that they will be difficult to replace.

"There are only 300 pairs known to remain in the wild and it appears they may have taken a breeding pair.

"They are particularly important part of our programme. This is a heavy blow."

Mr Donnison said the damage to the security fence had also left the remainder of the birds vulnerable to predators such as foxes, which could have been used as a way into the ground.

Police have recovered some evidence, which it is hoped will help in the apprehension of the culprits.

Mr Donnison said the fence had now been repaired and he stressed it was business as usual for visitors.