The deaths happened within a day of each other, and police believe the victims may have been housemates.

About 6pm on Saturday, a motorcycle rider crossed on to the wrong side of the Great Western Highway into the front of a semi-trailer and was killed.

They believe the victim was a 52-year-old man who lived in a unit on View Street, Chatswood.

View Larger Map

About 3pm yesterday, police were called to the same unit, following concerns about a resident.

When officers banged on the door and got no response, they broke in. Officers searched the house and found the body of a woman.

"The location and apparent injuries to the body have caused investigators to determine the death is suspicious," a police spokesperson said.

Police are trying to establish whether the body is that of a 48-year-old woman who lived at the address.

A strike force has been set up to investigate the two deaths.

- Jonathan Swan