Democratic donor Ed Buck tried to stop a man he’d allegedly injected with methamphetamine from leaving his home to call 911 as he overdosed, prosecutors said.

The emergency call on Sept. 11 ultimately led to the arrest of the wealthy LGBT activist — who’s previously dodged criminal charges in the overdose deaths of two other men at his Los Angeles apartment.

The latest victim, identified in court papers as Joe Doe, said Buck “personally and deliberately” administered a large dose of methamphetamine on Sept. 4 at Buck’s West Hollywood apartment, prosecutors said, according to the Los Angeles Times.

The man fled Buck’s home, fearing he was overdosing, to seek medical treatment.

The 37-year-old victim returned Sept. 11 — when Buck gave him “two dangerously large” doses of methamphetamine, prosecutors said.

Buck, who has donated to Barack Obama and Hillary Clinton, tried to stop the man from leaving. But he managed to escape anyway and called 911 from a gas station.

The victim was treated at a hospital and survived.

Buck has been watched closely by the Los Angeles Sheriff’s Department ever since the fatal overdoses of Gemmel Moore, 26, in 2017 and Timothy Dean, 55, in January, LA County Sheriff Alex Villanueva told the LA Times.

Buck, 65, was charged Tuesday with one felony count each of battery causing serious injury, administering methamphetamine and maintaining a drug house. If convicted, he faces a maximum of more than five years behind bars.

Prosecutors said the well-known political donor preyed on his victims as part of his “sexual fetishes.”

With Post wires