A man has been arrested after a house fire in Sydney’s inner west claimed the life of 80-year-old Ted Grantham.

Just after 4am, emergency services were called to Irrara Street, Croydon, after reports of a fire.

Crews extinguished the blaze, which badly damaged the home and caused the roof to collapse.

Grantham’s body was later found inside the home.

The organ player at the local church was remembered as a loving father and husband.

Investigators said the cause of the fire was unknown, but it was being treated as suspicious.

Police launched an appeal for public assistance to find a 50-year-old man, who police said was related to and living with the older man, and arrested him in Woy Woy about 7.40pm.

Detectives from Burwood are headed to Gosford police station, who police claim was found with a machete hidden in his pants.

No charges have been laid.

Superintendent Christine McDonald hailed the efforts of police from Burwood and other parts of the state.

“This has been an intensive few hours to locate a man we believe can assist with our inquiries into what we allege is a suspicious fire, and I thank my officers and all other officers who provided their assistance,” she said.

McDonald earlier said the blaze was “certainly not gang-related” and was not at this stage linked to any other fires.

McDonald said an elderly woman was also assisting police with inquiries.

She said all three parties – the woman, the 80-year-old man, and the 50-year-old man – appeared to be related.

She also confirmed the 50-year-old was known to police.

The woman is understood to have been at the house last night, but left about 1am.

McDonald said police were not called to the home before the fire broke out.