Ryan Munro, 18, collapsed in front of the main stage and was taken to Raigmore Hospital in Inverness where he later died. Police were last night understood to be investigating if drugs had played any part.

About 35,000 music fans gathered for the two-day event held on the banks of Loch Ness. The festival saw performances from Fat Boy Slim, The View and Razorlight, with fans basking in sunshine.

It is the second year in a row Rockness has been marred by a tragic death, but police last night praised the behaviour of revellers after making only a small number of arrests.

At last year's event, company director Paul Litterick, 39, from Dundee, was found slumped in his car after dying from a suspected drug overdose.

Last night, Mr Munro's shocked family described him as a warm-hearted boy who "lived life to the full". They said the avid Rangers fan was a "normal teenager" with a wide circle of friends. In a statement, the family said: "Ryan was affectionate, caring, fun-loving, warm- hearted and lived life to the full.

"He was enjoying his apprenticeship as a bricklayer and was looking forward to starting college. His passing has left all the family heartbroken and in a state of shock. What should have been a fun weekend has turned into a tragedy."

Dozens of tributes have been paid to Mr Munro – from the village of Hopeman in Moray – by friends on his Bebo website since his death on Saturday.

A post-mortem examination is expected to be carried out over the next few days.

Superintendent David O'Connor, who was in charge of police operations at the music festival, said: "It is obviously very sad when a young man loses his life. Investigations are continuing in to the death, but there do not appear to be any suspicious circumstances."

Jim King, the director of Rockness, said the thoughts of everyone involved with the festival were with Mr Munro's family.