A federal judge presiding over the criminal case against former FTX chief executive officer Sam Bankman-Fried has ordered he not have any contact with current or former employees of the exchange as part of his bail conditions.

In a Feb. 1 ruling, Judge Lewis Kaplan of the Southern District of New York said Bankman-Fried was to be prevented from communicating with current or former employees of FTX or Alameda Research “except in the presence of counsel” in order to remain free on bail through his trial. As part of his ruling, Kaplan added that SBF could not contact anyone with encrypted messaging applications like Signal — prosecutors claimed in earlier filings that the former FTX CEO had used the app to reach out to FTX US general counsel Ryne Miller.

“The undisputed information available to the Court regarding the ‘nature and seriousness of the danger [. . .] posed by [defendant’s continued] release’ on the existing conditions has changed substantially since he was released, and there appears to be a material threat of inappropriate contact with prospective witnesses,” said Kaplan. “That risk, the Court finds, is clearly and convincingly sufficient to warrant the imposition of additional conditions pending the full argument of the cross-applications.”

According to Kaplan, SBF was behind decisions to automatically delete Slack and Signal communications between FTX and Alameda employees starting in 2021, telling former Alameda CEO Caroline Ellison any potential legal case would be more difficult to build without proper documentation. He also cited Signal messages with Miller and other methods contacting “other current and former FTX employees” in his ruling.

The judge has yet to decide on whether SBF could be barred from accessing FTX and Alameda funds as part of his bail conditions as well. The Justice Department argued in a Jan. 30 filing that Bankman-Fried had reached out to FTX CEO John Ray to discuss ways to access the company’s funds. Judge Kaplan said he will listen to arguments on the matter in a Feb. 7 hearing.

Related: FTX sister company Alameda Research sues Voyager Digital for $446M

Bankman-Fried’s trial is scheduled to begin in October in U.S. District Court in the Southern District of New York, where he faces eight criminal counts including wire fraud. FTX’s bankruptcy case is also currently underway in the District of Delaware, where debtors recently requested subpoenas for information and documents from SBF’s family members.