Leissner, who took over the role in mid-2014, had helped arrange the sale of U.S. dollar bonds for Malaysian state investor 1Malaysia Development Bhd (1MDB), currently at the center of judicial investigations in multiple jurisdictions, sources told Reuters in February.

Earlier on Tuesday, the Wall Street Journal reported that Leissner, who had been placed on leave since January, quit after a review of his emails found that he had allegedly sent an unauthorized reference letter on behalf of an individual to another financial firm in 2015. http://on.wsj.com/1M3YnHj)

The source confirmed the details in the report.

A Goldman Sachs spokeswoman declined to comment on Leissner.

Leissner himself did not respond to a request for comment. The source declined to be named due to the legal sensitivities of the matter.

In a separate report, Bloomberg said Leissner had been subpoenaed by the U.S. Justice Department in a money laundering probe linked to 1MDB.

Leissner was issued the subpoena in late February, Bloomberg reported, citing people briefed on the matter.

(http://bloom.bg/1p3L9Fn).

There was no immediate response from 1MDB when asked about Leissner.

A spokeswoman for Singapore's central bank said in a statement Leissner was not based in Singapore when his alleged involvement in the 1MDB deals took place.

U.S. prosecutors are investigating whether funds were embezzled from 1MDB by politically connected people in Malaysia, Bloomberg reported.

The U.S. Justice Department and the FBI could not be reached for comment outside regular business hours.

The U.S. government is reviewing Goldman's business relationship with the Malaysian wealth fund as part of a broader, wide-ranging investigation into 1MDB, an FBI spokeswoman told Reuters in October.

(Reporting by Ismail Shakil in BENGALURU and Saeed Azhar in SINGAPORE; additional reporting by Anshuman Daga; Editing by Gopakumar Warrier and Miral Fahmy)