A portly ex-Colombo mob boss is suing the feds for $10 million over a slip-and-fall during a prison ping-pong match.

Thomas “Tommy Shots” Gioeli was enjoying a game of table tennis at Brooklyn’s Metropolitan Detention Center near a “leaky slop sink pipe,” and slipped in the grimy liquid, according to court papers.

The Post first reported Gioeli’s tumble in 2014, after he filed the initial complaint which conveniently left out the details of his prison extracurriculars.

In an ironic twist, the bloated mob menace known for strongarming others, busted his own kneecap during the fall, and it required surgery, according to the suit.

The slip occurred in August 2013 while the chunky mafia boss — who carried a “man purse” to trial — was waiting for assignment to a prison to serve his 18-year sentence for racketeering and conspiracy to commit murder.

The feds said the mafioso was alleged to have carried out a series of murders, including the 1997 retaliatory slaying of NYPD officer Ralph Dols for marrying another mobster’s wife, but was acquitted of those charges in 2012.

Gioeli was in part done in by a mob rat’s spouse, who turned over a scrapbook kept by Gioeli’s wife, Maureen, to the FBI. The pictures showed the Mafia boss fraternizing with other known wiseguys.

It also didn’t help that the fed-up crook called in to a radio show to whine about his upcoming trial, which he over-dramatically referred to as “a lynching.”

“The jury’s tainted, the jury’s tainted, the jury is soooooooo tainted with this story and that and my toenails and my teeth and I’m probably one of the most hated men in New York for no reason at all,” Gioeli bizarrely griped to AM 970 host Frank Morano in March 2012.

The germaphobe appeared to be referencing recent coverage of his concerns about his dentures and the cleanliness of his jail facilities, and the revelation that he was scarfing down commissary doughnut sticks, candy bars and potato chips — while complaining about his heart disease and diabetes in court.

The hefty lawsuit cites negligence on the part of the government, but in court papers prosecutors argue that the accused killer should have known the risks that come with playing ping-pong.

Gioeli remains behind bars at the FCI Butner Low Correctional Facility, in North Carolina.

Neither Gioeli’s attorney nor the Bureau of Prisons returned messages.