Gilgo Beach serial killer Rex Heuermann was disciplined for drug possession and smuggling a package into the infamous “Little Siberia” prison where he’s set to spend the remainder of his days.

Heuermann, 62, was caught by correctional officers in mid-July trying to smuggle something into prison, and was later found with unspecified drugs, according to disciplinary records obtained by The Post.

The twisted killer is currently locked in one of New York state’s oldest prisons, a bleak facility isolated in the frigid Adirondack Mountains near the Canadian border that’s now home to some of the nation’s most notorious killers.

The records did not say what drugs he was caught with nor what was in the package he was attempting to smuggle into the prison.

Heuermann is now due for a hearing on the matter on Sept. 18, according to prison records.

This is a developing story