The cause of the blaze that killed the father of the so-called ''Family from Hell'' may not be known for days or even weeks.

Detectives were yesterday still trying to establish if the fatal blaze in Fraserburgh was started deliberately.

They are still not ruling out that an apparent fight involving fire victim Gordon Graham, other members of his family, and some locals might be linked to the fire. A post-mortem examination was carried out yesterday, but complicated test results could take several days.

The charred remains of his body were found in the second-floor flat he occupied after the fire early on Sunday morning. He was so badly burnt, it took more than 36 hours to make a positive identification.

Detectives from throughout Grampian have been drafted in to help with inquiries into the fire, and search teams have scoured the area close to the building hunting for clues.

At the height of the inferno, Mr Graham's 40-year-old wife, Anne, was rescued from a window of the flat she lived in on the floor below.