A fit and cheerful 22-year-old student drowned during a late-night swim, an inquest has heard.

Ernestas Grigorenka, of Parsons Place, Norwich, was camping with 10 friends in Ickburgh, near Thetford, on August 24 and had gone to cool down in Lynford Water Conservation Lake.

He had been diving under water and did not emerge, prompting a frantic scramble by friends to find him.

Emergency services were called shortly after 11pm, with the student's body pulled from the water by the fire service at 1.45am on August 25.

Yvonne Blake, area coroner, concluded that Ernestas Grigorenka had died by misadventure at an inquest at Norfolk Coroner's Court on Friday.

Friends described him as a very fit guy and someone who could cheer anybody up.

Last year the basketball player had undergone an operation after injuring his metatarsal.

The inquest heard written testimony from friends saying after arriving at the camp they had played ball games, explored the area before starting drinking at around 6pm.

The group shared bottles of Jack Daniels, vodka and drank beer.

At around 11pm a small group went to the lake to cool down.

Mr Grigorenka, who was born in Alytus, Lithuania, went into the water with friends Laura Chrisanovaite and Greta Vainutyte.

Miss Chrisanovaite said they stayed close to the shore and her friend began diving in and out, and then did not emerge.

The inquest heard thought he was playing a prank but quickly became concerned for him and started yelling 'where's Ernestas?'.

The group called emergency services and began a search using torches on their phone.

Miss Chrisanovaite said: "Ernesta started diving in and out of the water for short periods of time. I saw him go back under for a second time, he was about 10 metres away from where I was standing.

"He never shouted for help.

"He was not drunk, he was still aware of what he was doing and knew to stay close to the shore due to his leg.

Miss Vanutyte said they had not been in the water any longer than 10 minutes.

A post mortem examination found the 22-year-old had no external injuries and concluded the medical cause of death was by drowning.

He was found with 166mg in 100ml of blood, the equivalent of being two times over the drink-drive limit.

Ms Blake said: "There isn't always a big splash. He went under the water and whatever happened, happened then.

"They were having fun, he had some drink but not enough to be intoxicated he was able to still walk, talk and wasn't slurring his words.

A group went into the water, he was diving under the water two or three times. He looked very happy.

"He went down and they became concerned because he was playing a prank and they started searching for him.

He has gone to cool down and lark about and unfortunately he drowned. It wasn't an expected result."

She addressed Mr Grigorenka family and said: "I am so sorry one does not expect to bury their child. My condolences to everybody who knew him and liked him."