This stool pigeon isn’t just helping the feds prosecute a bunch of reputed gangsters — he’s also hounding the daughter of one of the wiseguys online.

Mob turncoat Stephen Sabella posted a series of profane and typo-ridden messages on the Facebook page of Michelle Wright, whose dad, John “Porky” Zancocchio, faces a Manhattan federal racketeering trial along with six cronies later this month.

Sabella’s note to Wright referred to Zancocchio — a reputed Bonanno family capo and consigliere — as a “f-g coward” and that “horse tooth father of yours.”

“Also, if dad ever has balls to meet up with me ono [sic] on one I would love it but he a f-g blow jog that be hind bars for a while lol,” Sabella wrote.

In addition, he made a vile, racist comment about Michelle’s biracial daughter, writing, “why don’t you have another n—-r Baby.”

A source familiar with the case identified Sabella as the mob rat who on Jan. 27 was accused of serving as a prosecution “spy” by gleaning defense strategy from his former lawyer, who is currently representing one of Zancocchio’s co-defendants, reputed Bonanno enforcer Albert “Al Muscles” Armetta.

Sabella, 52, was also identified as the informer by the Gangland News website late last week.

Sabella secretly pleaded guilty to unspecified racketeering charges on Jan. 22 after serving as an FBI confidential source for three years, according to Gangland News.

In 2014, Zancocchio and a co-defendant, Joseph “Joe Valet” Sabella, allegedly assaulted Stephen Sabella, who is not related to Joe Valet, a source said.

Stephen Sabella posted his online rants shortly after The Post reported on how he was accused by several defense lawyers of extracting information from his former defense lawyer, Vincent Martinelli.

In the wake of those allegations, Manhattan federal Judge Alvin Hellerstein has scheduled a Thursday hearing requested by Martinelli to determine whether he has a conflict of interest in representing Armetta.

Meanwhile, Armetta has also hired another lawyer, Cesar de Castro, to represent him, court records show.

There was no answer Sunday at Stephen Sabella’s last known address on Staten Island.

Martinelli said he last represented Sabella in March 2017, nine months before Zancocchio and the others were indicted, after previously representing him in a 2008 federal racketeering case and a 2009 drug case for which Sabella was sentenced to four years in state prison.

Martinelli said Sabella was “presently represented as a cooperating witness” by defense lawyer Robert Fileccia, who didn’t return messages seeking comment.

Wright declined to discuss Sabella’s posts on her Facebook page.