Donald Trump's son has been called "unpatriotic" and "treasonous" over meetings he held with Russians by the president's former adviser in a new book.
Steve Bannon, the former White House chief strategist, is quoted criticising Donald Junior, claiming the Russia investigation would "crack [him] like an egg" in a new book seen by the Guardian.
The book, Fire and Fury by American journalist Michael Wolff, is based on hundreds of interviews, including with President Trump and key members of his inner circle.
According to Mr Wolff, Mr Bannon believes that the investigation into Russian interference in the presidential election is focusing on money laundering.
The former White House strategist is quoted heavily criticising a number of the president's inner circle, particularly his eldest son Donald Jr.
In July it was revealed that Donald Jr, held a meeting with a group of Russians took place during the 2016 election campaign at Trump Tower in New York.
The campaign staff had been promised documents that would “incriminate” rival Hillary Clinton ahead of the meeting.
But rather than alerting the FBI to potential Russian hacking of a political party's emails, Donald Jr agreed to a meeting, writing in an email: “I love it”.
After the meeting was revealed in a New York Times report, Donald Jr said none of the promised material was produced.
In reaction to the news, Mr Bannon told Mr Wolff: “The three senior guys in the campaign thought it was a good idea to meet with a foreign government inside Trump Tower in the conference room on the 25th floor – with no lawyers. They didn’t have any lawyers.
“Even if you thought that this was not treasonous, or unpatriotic, or bad shit, and I happen to think it’s all of that, you should have called the FBI immediately.”
He added: “You never see it, you never know it, because you don’t need to … But that’s the brain trust that they had.”
The Russia investigation led by special counsel Robert Mueller has already led to charges against four key members of Mr Trump's team.
They include Paul Manafort, Mr Trump's former campaign manager who was present at the June meeting at Trump Tower. Mr Manafort has pleaded not guilty to charges of money laundering.
But Mr Bannon warned that investigators will focus on money laundering, saying: “They’re going to crack Don Junior like an egg on national TV.”
“You realise where this is going,” he is quoted as saying in the book, due to be published next week.
“This is all about money laundering. Mueller chose [senior prosecutor Andrew] Weissmann first and he is a money-laundering guy. Their path to f***ing Trump goes right through Paul Manafort, Don Jr and Jared Kushner … It’s as plain as a hair on your face.”
The president and his campaign have denied any collusion with Russia and have accused the FBI investigation of political bias.
Last month it was reported that federal prosecutors had subpoenaed records from Deutsche Bank - something the White House has denied.
Discussing the reports, Mr Bannon said: “It goes through Deutsche Bank and all the Kushner sh**. The Kushner sh** is greasy. They’re going to go right through that. They’re going to roll those two guys up and say play me or trade me.”
Fire and Fury: Inside the Trump White House is due to be published next week.