The death of a 58-year-old man found behind a Queens building Wednesday morning was labeled suspicious, authorities said.

The man was discovered behind an apartment building on Steinway Street near 23rd Avenue in Astoria just after 9 a.m., police said.

He had several suspicious injuries, including a stab wound, sources said.

The medical examiner will determine the official cause of death, and the incident is likely to be classified as a homicide, the sources said.

The man’s identity was not immediately released.