As more than a billion fans watch Sunday’s Super Bowl, the FBI is eyeing current and former NFL stars off the field — looking for any links to an international drug and gambling ring.

Accused ringleader Owen Hanson, a former tight end at USC who played for then-coach Pete Carroll and won a national championship in 2004, was pals with a long list of gridiron stars, including retired Giants tight end Jeremy Shockey and his old USC teammate, 49ers running back Reggie Bush.

On Jan. 28, federal prosecutors in San Diego charged Hanson and 21 others with running a multimillion-dollar operation called ODOG Enterprise, which stretched from LA to Brooklyn to Australia. Ex-NFL running back Derek Loville, an ex-NFL running back and three-time Super Bowl champ, was among those busted.

The investigation is ongoing and appears to be widening, The Post has learned. According to a contact list belonging to Hanson — a copy of which The Post obtained — the alleged ringleader associated with dozens of pro athletes, including NFL, MLB and NBA players, and even police detectives.

Three agents last week paid a visit to Shockey at his home in Miami and quizzed him about his long friendship with Hanson, knowing that the two traveled together to Costa Rica in 2010 and flew back and forth between Miami and LA, where Hanson lived, to hang out. But Shockey told them he had no clue his pal was dealing coke or taking sports bets.

“I thought he was in the real-estate business like me,” Shockey told The Post. “I’m a straight businessman. I don’t hang out with drug dealers or prostitutes. I’m here with my girlfriend making out, and I get a knock on my door from these agents. I said to them, ‘Come on in. I got nothing to hide.’”

The investigators, who did not have a search warrant, asked Shockey how he met Hanson, the ex-player said. “We met when I passed out at a pool party in Vegas — from dehydration. He came to Miami all the time. I treated him like a friend. I let him stay at my house. He loved to surf. We’d go to the gym together. We went to the same parties together.

“I thought he was a very smart, nice guy. He was single. He was so cool. He was on the phone all the time. He knew everybody — DJs, celebrities. Pete Carroll knows him. Reggie Bush knows him; they were teammates at USC. This guy had money. He had cash on him all the time. But I thought it was from his business. No one knew any of this s–t was going on.”

He added: “I’m a drunk — I’m Irish. I’ve never had anything to do with drugs. And I would never do anything illegal to jeopardize what I’ve worked for.”

The agents showed him a photograph of two men, he said. “It showed a white guy I didn’t know. The other guy, Tank, I know through Owen.” The second man apparently was Giovanni “Tank” Brandolino, one of the accused leaders of ODOG Enterprise who was nabbed by the feds in Brooklyn.

The feds alleged in the indictment that Brandolino sent five grams of cocaine and 15 capsules of ecstasy from Orange, Calif., to a “pro-football player located in Nashville, Tenn.,” on Nov. 17, 2014 — the exact day the Pittsburgh Steelers beat the Titans there on “Monday Night Football.”

The Post asked the US Attorney’s Office in San Diego, the FBI and the NFL to identify the player. The prosecutors declined to comment. The others did not respond.

Loville, who stands accused of distributing drugs and collecting payments from customers, suggested to The Post that he was a dupe.

‘I’m a drunk — I’m Irish. I’ve never had anything to do with drugs. And I would never do anything illegal to jeopardize what I’ve worked for.’ - Jeremy Shockey

“You have friends, people you know but you don’t necessarily investigate every aspect of their lives, and I’ll just leave it at that,” he said.

Shockey confirmed Hanson had a wide circle of other friends, including basketball and baseball stars. Among the athletes appearing in the contact list, beside Shockey and Bush, was Dijon Thompson, a former NBA player and the second-round pick of the Knicks in 2005.

A professional Las Vegas gambler who calls himself Robin Hood 702 says he brought the case to the FBI.

He claims Hanson’s gang came after him when he refused to launder $20 million in drug proceeds, sending a DVD depicting a horrific decapitation to his house in Santa Monica and a picture of a man in a wrestling mask digging into the ground in front of his parents’ graves.

“I am the source that broke the case and I know the FBI will get to the bottom of this,” he told The Post. NFL Commissioner “Roger Goodell should start his own independent investigation of these allegations as well.”

He added: “I have full confidence in the FBI. I know they will find the truth. Without their tenacity in investigating this dangerous drug ring, my family and I would not be alive today.”

He has hired two attorneys, ­Patricia Glaser of LA and Pete Gleason in New York. Friday, Gleason sent a letter to the NFL demanding it provide around-the-clock security for his client.