Singapore plans to ban former Goldman Sachs banker Tim Leissner from its securities industry for 10 years as it investigates the 1MDB Malaysian investment fund scandal.

Leissner, who left Goldman Sachs in February, was sanctioned because he issued an unauthorised reference letter on behalf of Low Taek Jho, the Monetary Authority of Singapore (MAS) said in a statement on Friday.

Malaysian financier Low has been linked to alleged attempt to syphon billions from the development fund. He has denied the allegations.

In the letter, Leissner falsely claimed that Goldman performed due diligence tests on Low.

"These statements were untrue and were made by Leissner without Goldman Sachs' knowledge or consent," the MAS statement said.

The 1MDB scandal has been described as one of the largest in financial history. Billions were allegedly siphoned from the fund into personal bank accounts, including some belonging to Malaysian Prime Minister Najib Razak. Najib has been cleared of any wrongdoing by the Malaysian authorities.

Goldman made around $600 million in fees in 2012 and 2013 selling a total of $6.5 billion in bonds for 1MDB, its most lucrative deals anywhere in the world at that time.

Leissner, Goldman's key Southeast Asia deal-maker, was placed on leave by the bank and has since left it.

The letter cited in the MAS announcement was written by Leissner to help Low open an account in a Luxembourg bank. The account is not believed to have been opened. Low opened hundreds of bank accounts around the world, including Switzerland and Singapore, where he funnelled money taken from 1MDB, according to US, Swiss and Singaporean investigators.

"Today's announcement refers to a matter we discovered in January of this year and identified as a clear violation of the firm's standards," Goldman Sachs said in an e-mailed statement to Bloomberg.

"At that time we promptly took steps to separate Leissner from the firm and reported the matter to regulatory authorities in several jurisdictions, including Singapore. We continue to cooperate with the MAS."

Leissner has previously denied any wrongdoing. A lawyer for Leissner said his client had not been aware of any planned regulatory action by Singapore against him, the Wall Street Journal reported. Leissner has now been invited by Singapore authorities to respond and looks forward to doing so, the lawyer added.