UPDATE: CHARGES INCLUDE KIDNAPPING, FRAUD

STATEN ISLAND, N.Y. -- Richard Luthmann, the controversial lawyer who once challenged a legal adversary to a trial by combat and is currently sparring with the Staten Island district attorney and his wife, the borough's former administrative judge, was arrested Friday morning by FBI agents, according to U.S. Department of Justice.

Luthmann, 38, is scheduled to be arraigned at 2 p.m. in Brooklyn federal court when an indictment, detailing charges against him, will be unsealed.

Sources said the charges stem from some type of business dealing, although the exact nature of the business or the charges was not immediately known.

At least one other person may also be charged, said sources.

A spokesman for the FBI did not immediately return a phone call Friday morning.

A spokesman for Brooklyn federal prosecutors declined comment.

Luthmann could nit immediately be reached for comment.

Luthmann, whose local office is based on Victory Boulevard in Castleton Corners, is reportedly the subject of a separate state investigation by a special prosecutor requested by Staten Island District Attorney Michael E. McMahon.

In August, a Staten Island justice assigned a special prosecutor to probe allegations of criminal impersonation, forgery and falsifying business records made by one or more persons against an individual, who sources have identified as Luthmann.

According to media reports, Luthmann has been accused of creating false Facebook pages attacking McMahon and other political figures.

The judge's order does not specifically name Luthmann as the target.

It refers to three different "John Doe" matters; however, it is unclear whether the probe entails complaints made by three different complaining witnesses or multiple complaints made by one person.

The order cites "a potential grand-jury investigation into possible criminal activity," and empowers special prosecutor Thomas A. Tormey Jr. to explore "allegations of violations of criminal impersonation in the second degree, forgery in the third degree and falsifying business records in the second degree."

All of those charges are misdemeanors.

McMahon's application for the special prosecutor, originally filed in 2016, has been sealed.

Tormey has declined comment on the case.

Luthmann took a swipe at McMahon and his wife, Justice Judith N. McMahon, in a Facebook post after the assignment of the special prosecutor.

He wrote: "Richmond Count District Attorney ... is trying to set up a Special Prosecutor against me from an adjoining county to bring baseless 'harassment' or 'identity theft' charges. Any alleged activity is denied for the reasons previously stated. Moreover, any alleged activity is, arguendo, POLITICAL in nature and is PROTECTED SPEECH, at least in America and New York."

Earlier this week, Luthmann moved to quash a grand-jury subpoena he said was issued in state Supreme Court, St. George, to Facebook seeking information from his Facebook account.

He also sought a letter from prosecutors advising if he is the target of the investigation.

Luthmann's motion is on the court's calendar for Tuesday.

Luthmann represents Michael Pulizotto, the whistleblower who secretly recorded conversations of Justice McMahon, who was Staten Island's former administrative judge, other jurists and court personnel.

On Tuesday, Pulizotto filed a $2.9 million lawsuit in Manhattan federal court alleging Justice McMahon and personnel from the state Office of Court Administration and the New York State Court Officers Association bullied and harassed him while running the Staten Island Courthouse as a "fiefdom for their own personal and political gain."

In particular, Justice McMahon overstepped her authority on multiple occasions to aid her spouse, the district attorney, by conspiring with him to steer cases away from "defense-oriented judges," the complaint alleges.

John P. Connors Jr., Justice McMahon's lawyer has called the allegations "frivolous" and "baseless."

On learning of Luthmann's arrest on Friday, Connors said, "The arrest of Richard Luthmann by the FBI and the charges brought against him by the United States of America comes just three days after the filing of his baseless complaint against Judge McMahon. Judge McMahon remains confident that the system of justice to which she has dedicated her professional life will exonerate her and give Mr. Luthmann the justice he deserves."

A spokesman for the district attorney dismissed Pulizotto's suit as "the claims of a disgruntled and bitter ex-employee."

Pulizotto's federal suit comes on the heels of a $25-million slander lawsuit he filed in October in Manhattan state Supreme Court against Dennis Quirk, the head of the court officers'association.

According to that suit's civil complaint, Quirk cursed Pulizotto and denounced him as a "low-life rat" In a confrontation witnessed by several court officers outside the Staten Island Courthouse on Sept. 5.

Quirk told Pulizotto he knew Pulizotto had tape-recorded conversations with court personnel and given them to OCA's inspector general, alleges the complaint.

Quirk, the suit alleges, "has a strong political connection with" the McMahons.

Bruce Baron, Quirk's lawyer, has denounced the suit, calling it "as bogus as it gets" and said his client looks forward to his day in court.

While that suit only names Quirk as a defendant, it also targets the McMahons with allegations similar to those contained in the federal lawsuit.

Luthmann, a Game of Thrones fan, gained instant notoriety two years ago, when he asked a judge to sanction a trial by combat to resolve a civil suit against him as well as a countersuit he filed against his adversaries in that case.

State Supreme Court Justice Philip G. Minardo denied that request, and the cases later settled with the terms kept confidential.

In late 2015, Luthmann wrote a Brooklyn federal court judge saying he thought mobsters might have been after him and John Gulino, chairman of the Staten Island Democratic Party, may have knowledge of such actions.

Luthman wrote the letter to Judge Kiyo Matsumoto to explain his tardiness in submitting motion papers in a $20 million discrimination suit brought by his client, Lawrence Gilder, against Gulino and others.

Luthmann has failed in attempts to remove Gulino from power.

Gulino's lawyer had flatly denied the allegations, calling them "baseless," and the case was dismissed in September 2016, online federal court records show.