Former Goldman Sachs banker Tim Leissner, who has been linked to the 1MDB scandal, has been barred from the US securities industry for failing to provide documents for a regulator’s investigations.

The Financial Industry Regulatory Authority (Finra) said the indefinite ban on Leissner was issued on Sept 11 as he did not respond to requests for documents and other information, reported the Wall Street Journal (WSJ).

The US industry body was probing Leissner’s departure from Goldman Sachs in early 2016, in particular into a reference letter he allegedly wrote during his time with the firm.

“Without admitting or denying the findings, Leissner consented to the sanction and to the entry of findings,” the regulator wrote in Leissner’s file, according to WSJ.

Leissner, who was formerly Goldman Sachs’ Southeast Asia chairperson, was an adviser to 1MDB and had allegedly issued an unauthorised letter in June 2015 to a financial institution in Luxembourg vouching for controversial entrepreneur Jho Low, a key figure in the scandal surrounding the Malaysian sovereign wealth fund.

Goldman Sachs suspended him, and he later quit the firm. Subsequently, the Monetary Authority of Singapore (MAS) issued a 10-year ban against him trading in the country, effective March 13, 2017.

WSJ further reported that spokespersons from both Finra and Goldman Sachs declined to comment, along with Leissner’s lawyer.

It was previously reported that Leissner was a prime mover in Goldman Sachs’ effort in raising US$6.5 billion through the sale of three bonds in 2012 and 2013 for 1MDB, a deal where the firm supposedly made US$593 million in commissions.

Goldman Sachs has defended the fees as representing its underwriting risks and market conditions at the time.

US authorities are probing if the firm had reason to believe that some of the proceeds from the bond deals were not being used for their intended purposes, and had thus misled bondholders when it sold the securities issued by 1MDB.