A hulking former NYPD cop blew himself away Wednesday in front of FBI agents who were about to arrest him as part of a quadruple homicide and cocaine conspiracy, police sources told The Post on Wednesday.

Gerard Benderoth, 48 — nicknamed “White Rhino” from his days as a strongman competitor — killed himself on a quiet suburban road in Rockland County around 8:20 a.m. after feds pulled him over.

The feds planned to arrest him on a sealed indictment tied to a murder and drug conspiracy case, sources said.

US Attorney Preet Bharara had already busted Benderoth’s retired Westchester cop pal Nicholas Tartaglione in December — and slapped him with four murder charges along with drug conspiracy.

“If this guy put a bullet in his head rather than go and talk to them, he must have been in deep,” a law enforcement source noted to The Post.

Officers had tried earlier Wednesday to grab Benderoth at his ranch home in Stony Point in Rockland County, where he lived with his wife, Amy, and their four children.

Not finding him there, agents caught up with him one town south and some 15 minutes away, on windy Rosman Road.

Seeing flashing lights behind him, Benderoth called his former colleagues at the Haverstraw Police Department.

“Why are you pulling me over?” he asked, according to sources.

But Haverstraw cops told him it wasn’t them.

He stopped his SUV within sight of a church and up the street from an elementary school — and fatally shot himself before the agents could make it to his vehicle, sources said.

Benderoth, who worked a stint at the Haverstraw PD after retiring from the NYPD in 2005, was facing undisclosed charges in connection to the quadruple murder allegedly carried out by Tartaglione — a fellow bodybuilder and retired officer with the Briarcliff Manor PD.

Bharara’s indictment of Tartaglione, 49, accuses him and unnamed conspirators of selling kilo-weight cocaine for almost a year.

In April, one drug deal turned into a bloodbath, with Tartaglione allegedly killing Martin Luna, Urbano Santiago, Miguel Luna and Hector Gutierrez.

The ex-cop and the victims crossed paths at a bar his brother owned in Chester, NY, called the Likquid Lounge, Bharara said.

They were last seen together in a 2010 Chevrolet Equinox — and all four died in or near the bar, officials said.

Some of the four were involved in the conspiracy, and some were merely in the wrong place at the wrong time.

“These four men had not been seen or heard from since the day of their alleged murder,” Bharara said.

Within days of the December indictment, all four men’s bodies were recovered from Tartaglione’s rental property in Orange County, the feds said.

It’s unclear what role Benderoth may have played in the conspiracy.

The son of a retired NYPD homicide detective, the 300-plus-pound giant spent 12 years in the department, including a three-day stint helping recover bodies at Ground Zero after 9/11.

He was a regular at The World Gym in Haverstraw, where he would do 90 minutes of grueling power lifting at least once a week. Manager Joey Alonso called him a big “teddy bear.”

But Benderoth’s strength was astonishing. In 2008, he was named the 10th-strongest man in the country.

An online video from 2011 recorded him lifting 800 pounds; in 2010 he was filmed lifting 185 pounds via a one-armed “ape snatch.”

“My number one fan, and my hero, is me!” he joked in a 2012 nutritional supplement promotional video.

In another 2012 video, Benderoth — who had a giant tattoo of a black eagle from the German coat of arms on his shoulder — boasted that he ate a dozen eggs in

a sitting, and that “as soon as I wake up, I down a beer.

“Just one beer,” along with several bananas, he said.

“If it ain’t nailed down, you eat it,” he joked in the video. “If it’s nailed down, you rip it up with a crowbar and you eat it.”

By Wednesday afternoon, the FBI had not released Benderoth’s name, confirming only that a suicide had occurred during a traffic stop.

“While conducting a law enforcement vehicle stop this morning, FBI agents and task force officers approached a man who was the only occupant of a stopped vehicle,” a spokesperson told The Post.

“During the approach, the man drew a handgun and shot himself. He died of the self-inflicted wound.”

Tartaglione’s attorney declined to comment.

Family members also wouldn’t speak at Benderoth’s home, where he lived with his wife, 13-year-old son, twin 6-year-old boy and girl and 2-year-old daughter.

Additional reporting by Alex Taylor and Gabrielle Fonrouge