A man was fighting for his life today after he and a friend fell into a Sussex farm pond.

His friend managed to drag himself out of the water and was later taken to hospital.

Police were today searching for a third man - Joseph Brazil, 28, from Hurstpierpoint - who split from the others just before they reached the pond and is still missing.

Police were first called to a field near Swains Farm in Furners Lane, Henfield, at 1.40pm yesterday after a report of an abandoned van. Officers inspected the vehicle but found no one and left.

They were then called out again at 4.07pm after being told that a man was trapped in the pond.

Firefighters arrived to find a man floating unconscious in the water. The police helicopter flew him to Worthing Hospital and he was transferred by road to the Royal Sussex County Hospital, Brighton, where his condition is critical.

A second man in the pond, who had hypothermia, was taken to Worthing Hospital by ambulance and later released.

The three were thought to be travellers and relatives were today searching for Mr Brazil. Police have found a key at the pond which is thought to belong to him.

An underwater search team has been called in to search the pond, but a police spokeswoman said: "In the light of information provided by his friend at the time, there was no suggestion he had come to harm in the pond."

One traveller at the scene said: "We have been here all night trying to drag the pond with bits of old rope. This man has a wife and three kids - surely more should be done."

The family of travellers has been living in Stanmer Park, Brighton.

The police spokeswoman appealed for Mr Brazil to contact officers or his family.