Joe Biden's son Hunter has opened up about his battle with addiction in an extraordinary television interview overnight, saying that he smoked Parmesan cheese after mistaking it for crack cocaine.
The 51-year-old spoke to CBS about his struggles, his relationship with his father and his business dealings in Ukraine.
Speaking about his addiction, he said at its peak, he would spend days on end drinking vodka and smoking crack cocaine.
"I spent more time on my hands and knees picking through rugs smoking anything that resembled crack cocaine.
"I probably smoked more Parmesan cheese than anyone – than anyone you know."
He then told interviewer Tracy Smith: "I once went 13 days without sleeping and smoking crack and drinking vodka exclusively throughout that entire time."
He said that he "never" thought his dad would "give up on me".
The President's second son, a lobbyist and Yale-trained lawyer, said he was "co-operating completely" with a Department of Justice probe into his finances.
Federal investigators have been looking into the business dealings of the younger Biden, a person with knowledge of the probe told CNN.
The investigation is examining multiple financial issues, including whether Biden and his associates violated tax and money laundering laws in business dealings in foreign countries, principally China, according to two people briefed on the probe.
He added: "And I am absolutely certain, 100 per cent certain that at the end of the investigation, that I will be cleared of any wrongdoing."
Biden also addressed reports that a laptop dropped off at a repair shop, which was handed over to the FBI, contained photos of him taking drugs and detailed his business dealings in Ukraine.
He suggested there could be a "laptop out there that was stolen from me".
"It could be that I was hacked, it could be that it was Russian intelligence. It could be that it was stolen from me," he said.
The laptop is also reported to contain a 12-minute video that appears to show him smoking crack while engaged in a sex act with an unidentified woman.
The New York Post also published a "smoking-gun" email that it alleged reveals how Hunter Biden introduced his father Joe to a Ukrainian businessman, Vadym Pozharskyi, when Biden Snr was Vice President.
Biden Jnr defended taking a position in 2014 on the board of Burisma Holdings, a Ukrainian energy company that played a role in former President Donald Trump's first impeachment, saying he underestimated how it would be used against him.
"I don't think I made a mistake in taking a spot on the board. I think I made a mistake in terms of underestimating the way in which it would be used against me," he told CBS in the new interview," he said.
"All I know is that not one investigative body, not one serious journalist, has ever come to the conclusion that I did anything wrong, or that my father did anything wrong."
Both Bidens have denied any wrongdoing, and the President's campaign denied the alleged meeting with Burisma boss Vadym Pozharskyi ever occurred.
Hunter's book, which is set to be released on Tuesday, chronicles his life to date, with lengthy passages on his close relationship with his late brother, Beau Biden, and it sheds insight on what it was like to grow up the son of Joe Biden.
He recalled during the CBS interview an episode in which his father, who was vice president at the time, paid him a visit to confront him about his drinking.
"He came to my apartment one time, and this is when he was still in office as vice president. And so he ditched his Secret Service, figured out a way to get over to the house, and I said, 'What are you doing here?' He said, 'Honey, what you doing?' I said, 'Dad, I'm fine.' He said, 'You're not fine.'"
That incident led to a spell in rehab, he said.
Biden also said in the interview that he and his father speak every day, with the President generally calling him every night before bed.
"Not only does he talk to me every night, but he calls every one of my daughters, he talks to each one of them every day. And he talks to me."