A student fell into a swollen Oxford river and drowned after drinking free Champagne and cocktails at a party.

Flooding and the foot and mouth emergency halted searches for Oxford University student Wallace Watson, 18, and it was a month before his body was found at Waterman's Reach marina, off the Thames, near Abingdon Road.

An inquest heard yesterday that the first-year chemistry undergraduate went missing after a ski club party, at the Oxford Union, on Friday, February 16.

When his body was found, pathologist Dr Peter Millard, of the John Radcliffe Hospital, Headington, said Mr Watson had 273mg of alcohol in 100ml of blood and 344mg of alcohol in 100ml of urine -- both amounts were three times the legal driving limit.

Mr Watson, from Letcombe Bassett, near Wantage, was a student at St Catherine's College, in Manor Road.

Fellow undergraduate Oliver Hayes said that on the night of the black-tie party he met Mr Watson, who said: "Let's go and get drunk."

Later, Mr Hayes and another friend, Benedict Shuttleworth, saw him sitting on the stairs near the Union exit.

Mr Shuttleworth told the inquest the party had free Champagne and cocktails.

He said: "Wallace was his normal, happy self. I don't know how much he'd had to drink, but I imagine he had quite a lot by then. He was slightly louder than usual."

Later in the evening, a number of people saw a man matching Mr Watson's description walking down St Aldate's.

WPc Stephanie Hancock said: "The man was walking towards the police station. He was giving the impression that he was drunk."

Postgraduate student Rachel Buxton was walking home when she saw a man vomiting over Folly Bridge.

She said: "He was clearly very unsteady on his feet."

The inquest heard that although no-one saw Mr Watson fall into the fast-flowing and very cold river, a number of people spotted him struggling in the water.

Student Oliver Butt swung his bag over the side of Folly Bridge to reach him, and Alexander Banks, a student at Merton College, fell into the water when he tried to reach the teenager.

When paramedics and police arrived Mr Watson had vanished.

Sgt Sarah Price said flooding hampered helicopter, thermal imaging and underwater searches. She said boats could not be used due to foot and mouth restrictions.

John Scott, of Marlborough Road, spotted the body four weeks later as he walked to work.

Oxfordshire coroner Nicholas Gardiner recorded a verdict of accidental death by drowning.