Detectives have appealed for anyone who saw a 65-year-old man from west London in the past two months to contact them as part of an investigation into his death.
Michael O'Donnell from Southall was found dead at a property on Samara Drive on Wednesday morning.
The discovery was made after concerns were raised about his welfare and about the state of the premises.
A 54-year-old man and a 28-year-old woman have been arrested on suspicion of murder and remain in police custody, the Metropolitan Police said.
The man is also being questioned on suspicion of preventing a lawful burial.
Met officers have asked locals to consider whether they had seen Mr O'Donnell since Monday 24 February, whether alone or with another person.
A woman who lived in the same building as Mr O'Donnell said described him as "very kind and a very nice guy".
Neighbours said Mr O'Donnell was frequently visited by his son, but otherwise kept to himself.
