A man has been found dead in the front yard of a house in Melbourne's east, with homicide detectives investigating.

The man was found dead at the property in Milne Street, Mitcham, about 7.30am on Friday.

Police are treating the discovery of the body as suspicious, and say the cause of death is not yet known.

Channel 7 has reported the man was aged in his 50s and lived in the house, but police are yet to confirm his identity.

A neighbour, who wished to remain anonymous, said the family living at the house "keep to themselves".

"There's a family there and a trampoline and some play equipment in the front yard," the man said.

Milne Street was cordoned off on Friday and police forensic vans lined the road.

On Friday afternoon, police said the results of a post-mortem would determine whether the death would be treated as a homicide.

The results may take several days, they said.

"The exact circumstances surrounding the death are yet to be determined but investigators are treating the man's death as suspicious," a police spokeswoman said.

Anyone with information is urged to call Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au.