By Jody Godoy and Luc Cohen

NEW YORK (Reuters) -Nishad Singh, the former director of engineering at now-bankrupt cryptocurrency exchange FTX, pleaded guilty to U.S. criminal charges on Tuesday, and agreed to cooperate with prosecutors' investigation into FTX founder Sam Bankman-Fried.

"I am unbelievably sorry for my role in all of this," Singh said, adding that he knew by mid-2022 that Bankman-Fried's hedge fund, Alameda Research, was borrowing FTX customer funds, and customers were not aware. Singh said that he would forfeit proceeds from the scheme.

Bankman-Fried, FTX's founder, pleaded not guilty to eight criminal charges filed against him in December. Prosecutors say he stole billions in FTX customer funds to plug losses at Alameda. He has acknowledged inadequate risk management, but says he did not steal funds.

Singh, 27, pleaded guilty to one count of wire fraud, three counts of conspiracy to commit fraud, one count of conspiracy to commit money laundering and one count of conspiracy to defraud the United States by violating campaign finance laws.

He traveled back from the Bahamas shortly after FTX imploded in November in part to assist the U.S. investigation, prosecutor Danielle Sassoon said at Tuesday's hearing. He was released on $250,000 bond.

Bankman-Fried, 30, now faces 12 criminal charges after prosecutors unsealed a new indictment against him last week. A spokesman for Bankman-Fried declined to comment.

Singh is the third Bankman-Fried close associate to plead guilty and cooperate with the probe. Caroline Ellison, who was Alameda's chief executive, and Gary Wang, who was FTX's chief technology officer, pleaded guilty in December to seven and four criminal charges, respectively.

"He wants to do everything he can to make things right for victims, including by assisting the government to the best of his ability," Singh's lawyers, Andrew Goldstein and Russell Capone, said in a statement.

Separately on Tuesday, the U.S. Securities and Exchange Commission and the Commodity Futures Trading Commission filed civil lawsuits against Singh.

'STRAW' DONORS

Bankman-Fried rode a boom in the values of bitcoin and other digital assets to amass an estimated $26 billion net worth and become an influential U.S. political donor.

Singh also became a major donor to Democratic politicians, contributing $8 million to campaigns in the 2022 election cycle, according to OpenSecrets.

In the new charges filed last week, prosecutors said Bankman-Fried conspired with two other former FTX executives to donate tens of millions of dollars to influence lawmakers to pass legislation favorable to the company.

The donations were illegal because they were made with "straw" donors or corporate funds, prosecutors said. They said Bankman-Fried directed another FTX executive, identified as CC-1, to donate more than $21 million to a pro-LGBT group.

Federal Election Commission records show that Singh contributed $1.1 million on July 7, 2022 to the LGBTQ Victory Fund, a national organization dedicated to electing openly LGBTQ people.

Singh said in court that he agreed in 2022 to make political donations in his own name that were funded in part by transfers from Alameda, without providing details of the donations. He said that while he agreed with the political leanings of those he donated to, he did not select the candidates.

Singh was a close friend of Bankman-Fried's younger brother in high school, Bankman-Fried wrote in a deleted blog post.

"Today's guilty plea underscores once again that the crimes at FTX were vast in scope and consequence," Damian Williams, the top federal prosecutor in Manhattan, said in a statement.

"They rocked our financial markets with a multibillion-dollar fraud. And they corrupted our politics with tens of millions of dollars in illegal straw campaign contributions."

(Reporting by Luc Cohen and Jody Godoy in New York; Editing by Matthew Lewis and Bill Berkrot)