Staten Island attorney Richard Luthmann already is fighting federal charges alleging he tried to defraud customers of his scrap metal business, and help a co-defendant collect a debt at gunpoint.

NY1 has learned that a state grand jury has been taking testimony about phony Facebook pages he created in the names of prominent borough politicians.

NY1 first revealed Luthmann's role in the pages last August. We showed how the pages were made to look like those of candidates for state Assembly, the City Council, and district attorney. The posts often contained content embarrassing them, like one on the page created in the name of Janine Materna, who lost a Republican primary for the Assembly in 2016. "Mayor Bill de Blasio is right. We need a homeless shelter in Annadale," the post reads.

NY1 reported that Luthmann was the pages' administrator and had many online conversations boasting about them.

Our reporting triggered an investigation that led to the appointment of a special prosecutor. NY1 has learned that at least four Staten Island politicians recently testified before the grand jury, including City Councilwoman Debi Rose and District Attorney Michael McMahon, who were victimized by the misleading accounts, and Councilman Joe Borelli, whom Luthmann had told about one of the pages. Also testifying: Ron Castorina, who beat Materna in that 2016 primary and knew about Luthmann's role in the misleading pages.

Sources tell NY1 that the grand jury investigation includes a review of payments to Facebook to promote some of the misleading posts. One promoted post showed a photo of what appeared to be Materna's car, in a spot for the handicapped.

"To heck with the cripples," the post says. "I will park where I want."

The post generated 95 pages of comments, nearly all negative.

The misleading pages had a disclaimer, like this one for Materna's: "This is an UNOFFICIAL FAN PAGE." But it could have been overlooked by Facebook users.

Luthmann has called the pages dirty tricks but legal.

We spoke with Castorina, who said he too was a victim of Luthmann.

Borelli says he tried to discourage Luthmann from making the phony posts.  

The Brooklyn U.S. Attorney's Office says Luthmann has been held this summer at a federal lockup in Massachusetts for inmates needing medical or mental health treatment. His attorney did not respond to our request for comment. Sources say any action by the grand jury will be sealed until after Election Day.