A US federal judge on Friday ordered FTX founder Sam Bankman-Fried back to jail after prosecutors argued that he had violated the conditions of his bail and meddled with the case's witnesses, less than two months prior to his trial.

Bankman-Fried, 31, has pleaded not guilty to charges of wire fraud and conspiracy to commit money laundering, as well as election finance violations, in connection with the collapse of his cryptocurrency firm.

US District Judge Lewis Kaplan directed Bankman-Fried back into federal custody citing "probable cause... that the defendant has committed the federal crime of attempted witness tampering," the ruling read.

Prosecutors argued that Bankman-Fried's activities as a source for The New York Times amounted to witness intimidation, citing an article containing private writings of Caroline Ellison, Bankman-Fried's ex-partner, who formerly worked at Alameda Research and is a cooperating witness in the government's case.

Bankman-Fried is due to go on trial in early October.

FTX and its sister trading house Alameda Research went bankrupt in November, disintegrating a virtual trading business that at one point had been valued by the market at $32 billion.

Prosecutors allege that Bankman-Fried -- who had been released on $250 million bail and confined to his parents' California home before Friday's ruling -- cheated investors and misused funds that belonged to FTX and Alameda Research clients.

The former FTX chief had drew in huge investments from prominent fund managers and venture capitalists. But it all collapsed dramatically when a media report revealed that Alameda's balance sheet was heavily built on a token created by FTX with no independent value, exposing Bankman-Fried's companies as being dangerously interlinked.

Bankman-Fried was arrested at his apartment in the Bahamas on December 12 at the request of federal prosecutors in New York.