Police are now treating the death of a man found in a fire in a derelict house on Monday as suspicious.

Police sources have confirmed that the homicide and serious crime command are now investigating the incident.

Six fire engines from Purley, Croydon, Wallington, Addington and Norbury fire stations were called to The Waldrons, near Davenant Road at 2.45pm to reports of a fire.

About 35 firefighters and officers tackled the blaze and a London Firebrigade spokesman said they faced challenging conditions in the house. The fire was finally brought under control at 5.50pm.

Fire crews wearing breathing apparatus searched the basement and found a man but sadly he was pronounced dead at the scene.

The man has yet to be formally identified and the cause of the fire has yet to be officially explained.

The LFB had been called on Sunday evening to the building, which is owned and was once used by Croydon Sea Cadets, to put out a small fire in the house.

A spokesman said three fire engine were called to the scene at 7pm. He said there was no suggestion the two fires are connected.

In 2011 the house was badly damaged by fire on New Year’s Eve which saw the roof collapse.

A spokeswoman for the Marine Society & Sea Cadets said they were working with the Police and Fire Brigade with their investigation.

She said the building had been unused for several years but they still checked the site weekly. She added they were shocked and saddened that someone had died.