A man was discovered dead in a truck in Forest Lawn early Friday morning. (CBC/Leighton Klassen)

A man was found dead in southeast Calgary early Friday morning in what police are calling suspicious circumstances.

At about 1 a.m. a woman called police to report that a man was in medical distress at the 4300 block of 19th Avenue S.E.

When crews arrived at the address in Forest Lawn the man, believed to be in his 50s, was found dead in a truck, police said.

The homicide unit is investigating. An autopsy has been scheduled for next week.