A video posted to NFL prospect Laremy Tunsil's verified Twitter account Thursday night showed the former Ole Miss offensive tackle wearing a gas mask and smoking a substance from a bong. The tweet was deleted minutes after it was posted.

Tunsil, one of the highest-rated prospects in the draft who at one point was considered a likely No. 1 overall pick, was picked No. 13 overall by the Miami Dolphins. Tunsil confirmed to ESPN's Suzy Kolber that he was in the video, adding that he was "blessed" to be picked by the Dolphins.

A video tweeted from Laremy Tunsil's account Thursday showed him smoking a substance out of a gas mask. The tweet was later deleted. @kingtunsil78/Twitter

"It is B.S. Somebody hacked into his account," agent Jimmy Sexton earlier told ESPN.

Tunsil said "we're trying to find out" who hacked the account. He said at a news conference later Thursday that he doesn't plan to press charges if he does discover who is responsible for the hack.

There appeared to be another hack after he was chosen, with an image going up on his Instagram account showing a text message conversation, allegedly between Ole Miss assistant athletic director John Miller and Tunsil, about paying rent and electric bills for Tunsil's mother. Tunsil's Instagram account has since been deleted.

Tunsil told ESPN Radio on Thursday night that he did not know anything about the Instagram material and that he has no control over his social media accounts.

In a news conference at the NFL draft in Chicago, Tunsil admitted to reporters that he took money while at Ole Miss.

"I made a mistake. That happened," he said.

When reporters asked Tunsil if he meant he had taken money from a coach, he said, "I'd have to say yeah."

Tunsil was ushered out of the news conference when asked if he had met with NCAA investigators.

"We're very comfortable with all the information we have on the situation," Dolphins general manager Chris Grier said after the team had chosen Tunsil. "We had heard rumors, and we had done [background] work.

"The video is two years old. So from all the information we have, we are comfortable with it."

Ole Miss coach Hugh Freeze, who is in Chicago for the draft with Tunsil, said the video is "from a long time ago."

"How this came out today, I don't understand," Freeze said. "I don't know how. He doesn't deny it. He owned it."

Grier said the Dolphins never expected Tunsil to be there at No. 13.

"No, this is a guy who was No. 2 ranked on our board," Grier said. "We did not expect him to be there."

Tunsil told reporters that he doesn't have a drug problem.

"You can check all my college tests. I never failed one," he said.

Tunsil's Twitter account was deleted shortly after the draft began Thursday night.

Two offensive tackles were selected in the top eight picks Thursday, including Michigan State tackle Jack Conklin, picked by the Tennessee Titans after they traded with the Cleveland Browns to move up to the No. 8 spot. The Baltimore Ravens picked Notre Dame tackle Ronnie Stanley at No. 6.

Ravens general manager Ozzie Newsome said Thursday that his team had Stanley ranked above Tunsil. Asked if Twitter had any influence on the Ravens' pick, he said, "That's always a part any time you get information."

"Our scouts get a lot of information. When things happen, a lot of times we're not surprised," Newsome said. "We took the best player, the player who rated the highest on the board at that point. I cannot neglect the importance of the work our scouts do in the fall and in the spring getting information for us."

Asked if the New Orleans Saints would have considered any offensive players with the 12th overall pick, coach Sean Payton said they had to consider Tunsil as he kept falling.

"He's an extremely talented player, athletic. Then you start projecting, 'All right, who's going to guard?'" Payton said. "But I think we felt really confident with Sheldon [Rankins]."

Payton said it was "unusual" and a "tough deal" watching what happened with Tunsil, so he was glad to see him get drafted soon after.

"All the sudden for one player to have a closet door open, it's unfair," Payton said.

Tunsil was sued earlier this week by his stepfather, Lindsey Miller, who is accusing Tunsil of attacking him and defaming his character in an incident last summer.

Miller and Tunsil filed domestic violence charges against each other last year. Tunsil said he attacked Miller after Miller attacked Tunsil's mother, Desiree Polingo, and Miller said Tunsil attacked him unprovoked. The charges were dropped in August.

Miller's attorney Matthew Wilson said his client had nothing to do with Tunsil's social media accounts being hacked.

"We denounce whoever did this act," Wilson said. "It is abhorrent. It is cowardly and just patently wrong and illegal. Whoever did this should be prosecuted to the fullest extent of the law. We were surprised when it happened last night. It goes without saying, obviously, that we deny having anything to do with it."

The smoking video was posted to Tunsil's account at 7:47 p.m. ET Thursday. It begins with a man wearing a black gas mask with a plastic tube attached to the mouth. An unseen person holds a lighter to the tube, and smoke begins rising. The person wearing the mask adjusts it for about 10 seconds before raising it off his head and laughing. He coughs several times before the video ends.

Tunsil had to sit out the first seven games of the 2015 season after the NCAA ruled that he received improper benefits, including the use of three loaner cars.

At the scouting combine in February, Tunsil's former Ole Miss teammate Robert Nkemdiche told reporters that Tunsil was in the hotel room with him in December on the night he was injured falling off an Atlanta hotel balcony.

Nkemdiche, who was picked 29th by the Arizona Cardinals on Thursday, expressed sympathy for Tunsil's draft-day disaster.

"It's heartbreaking because I love that dude and he's such a good person," Nkemdiche said. "I can't wait to see what the does in the NFL."

ESPN's James Walker, Mark Schlabach and Jamison Hensley and The Associated Press contributed to this report.