A Staten Island lawyer has been outed as the prankster who created fraudulent Facebook accounts pretending be those of borough politicians.

An NY1 report identified Richard Luthmann as the provocateur who slimed former Republican Assembly candidate Janine Materna, Democratic City Councilwoman Debi Rose and even Staten Island District Attorney Michael McMahon.

Materna had filed a complaint over the harassment and threats triggered by the phony site.

“I filed a police report last year when my life was threatened on the Facebook page due to the things that were posted,” Materna said Thursday.

The bogus Facebook page in the name of Rose falsely claimed she was in favor of a “heroin-methadone den” in her council district.

Luthmann, who once tried to settle a legal beef with a duel, told The Post Thursday that the pranks were satire.

“This is protected by the First Amendment. These people are public officials, public candidates,” he said.