A former fire chief has told a murder trial that his report into the death of a man in Fraserburgh in 1998 concluded it was accidental.
Barry Henderson, 42, denies killing Gordon Graham, 43, and attempting to murder his wife Anne in a fire.
Witness Alistair Spence said he determined the blaze had been started by a cigarette being dropped on a mattress on the stairs.
He told the High Court in Glasgow it could still be wilful fire raising.
In his report, Mr Spence said it would have only taken two minutes for the mattress to be well alight.
Prosecutor Jim Keegan QC asked: "Would you still say the fire was accidental?"
Mr Spence replied: "There is always a chance it could be wilful fire raising."
Mr Henderson denies all the charges against him and has lodged special defences of alibi and incrimination.
The trial before Lord Ericht continues.