A New Jersey man returned home Monday to find his wife and her lover dead in a car in the garage, NBC New York reported.

The bodies of the 39-year-old woman and 56-year-old man were discovered at a home in Newark, New Jersey Monday night.

Sources told NBC New York the wife and the man were having sex in a car in the garage when they were killed by carbon monoxide gas. Police said the dead man was a mechanic and that they believe the wife was paying for her car work with sex.

The incident remains under investigation.