Sam Bankman-Fried is heading to jail after a U.S judge on Friday revoked his bail, finding probable cause that the indicted founder of the bankrupt FTX cryptocurrency exchange tampered with witnesses at least twice.

U.S. District Judge Lewis Kaplan’s decision to jail the 31-year-old former billionaire ahead of his Oct. 2 fraud trial over FTX’s November 2022 collapse came after prosecutors said he had “crossed a line” by sharing private writings by former romantic partner Caroline Ellison with a New York Times reporter.

“He has already - without violating any other bail condition save that he not commit another crime - gone up to the line over and over again,” Kaplan, who is known for his no-nonsense demeanor in the courtroom, said in a hearing in Manhattan federal court.

The judge rejected a defense request to delay Bankman-Fried’s detention pending appeal of the decision.

The decision could complicate Bankman-Fried’s efforts to prepare for trial. He faces charges of having stolen billions of dollars in FTX customer funds to plug losses at his Alameda Research hedge fund, where Ellison was chief executive officer.

She has pleaded guilty and is expected to testify against him at his Oct. 2 trial.

Bankman-Fried, who has pleaded not guilty, sat with his shoulders hunched, leaning forward on the table and fidgeting with a Post-It note as the judge order him detained.

He had a blank expression as he was led out of the courtroom in handcuffs by members of the U.S. Marshals Service after removing his shoelaces, watch, jacket and tie and emptying his pockets.

Bankman-Fried’s parents, both law professors at Stanford University, were present in the courtroom’s audience. His mother, Barbara Fried, nodded to him in tears as he left. His father, Joseph Bankman, placed his hand over his heart as he watched his son be led away.

Bankman-Fried rode a boom in the value of bitcoin and other digital assets to build a net worth of an estimated $26 billion and become an influential political donor in the United States, but FTX’s collapse wiped out his fortune. He later said he had $100,000 in his bank account.