A police officer spent 30 minutes in a freezing river holding an unconscious man's head above the water.

Mystery surrounds how the struggling man came to be in the icy Cod Beck, in Thirsk, North Yorkshire.

The unnamed man's cries alerted locals to his plight, at about 12.30am yesterday.

Sergeant Robert Bowles, of Thirsk police, jumped twice into the bitterly cold water, but because of the height of the river banks it took half an hour for him and his colleagues to rescue the man.

The first time he jumped in, he was unable to get the man out, so he tried again further down stream. The officer was left cold, but unhurt.

The man, who was unconscious when he was pulled to safety, near Nursery Gardens, is thought to be originally from Wales, but working locally.

He was taken to the Friarage Hospital, Northallerton, where he recovered consciousness. Last night, he was in a stable condition.

A police spokesman said: "A local resident contacted the police to report he could hear a man shouting for help.

"Police officers responded and after a search located a man in the water."

The rescued man is aged 30, with dark hair and he was wearing a distinctive navy blue top with white stripes.

Police believe an incident in the Waterside area, close to Nursery Gardens, may be linked.

A couple were reported to be arguing at about midnight and police believe the man involved was the same person pulled from the beck.

The woman seen arguing was described as in her late 30s, about 5ft 4in and with light hair. Police are not treating the incident as suspicious but are keen to talk to her.

Anyone who can help to identify the man is asked contact police on 0845-60-60-247.

* The rescue comes days after teacher Adrian Tavener went to the aid of a stricken woman.

He dived into the icy River Tyne to save the woman, who had fallen 80ft from the Tyne Bridge.

In October, two teenagers were rescued from the roof of a Ford Escort stuck in Stanhope Ford, in Weardale, County Durham.

And in December last year, a family of four were carried to safety from their car by police who waded into the ford.