Kimora Lee Simmons and Tim Leissner
Kimora Lee Simmons and husband Tim Leissner attend The Weinstein Company & Netflix's 2014 Golden Globes After Party Getty

Tim Leissner, the high flying banker who helped build up Goldman Sach's business in Malaysia, officially left the company earlier this month. His departure was confirmed by the company's spokesman Edward Naylor but no details were given.

Goldman Sachs has no plans to appoint a replacement. According to CNBC, the post vacated by Leissner was more of "an emeritus status than an operational function." Leissner. has not been accused of any wrongdoing.

However, the FBI is reported to be investigating Leissner's connections to Malaysian Prime Minister Najib Razak, who himself is mired in the state fund scandal. Najib is the chairman of 1MDB's advisory board.

The FBI is not the only one taking a closer look at the state fund's activities. Switzerland, the UK, Hong Kong and Singapore are among others who are probing various leads, including possible money laundering and bribery.

CNBC noted that since the scandal surrounding the state fund deepened, Goldman Sachs has struggled to win new business in Malaysia. It has slipped down the league tables there after experiencing a golden era in the country and ranked as the most prominent international bank.

The investment bank has worked on $18.6bn of Malaysian mergers and acquisitions over the past five years, making it the top foreign adviser with a 20.5% market share, according to data complied by Bloomberg. It was ahead of Bank of America Corp and beat all local rivals except CIMB Group Holdings Bhd and Malayan Banking Bhd.

Leissner has been with Goldman Sachs for almost 18 years in Asia and was the chairman of the investment bank's Southeast Asia operations, based in Singapore. However, as the bank's dealings with the scandal hit Malaysia's state fund 1Malaysia Development Berhad unravelled, he moved to Los Angeles at the end of 2015 and subsequently took personal leave from the US bank in January.

According to CNBC, people close to the bank claim that Leissner's wife, former model and entrepreneur Kimora Lee Simmons, is building a fashion business in Los Angeles and the banker has been staying in the city more frequently over the past two years. This has apparently caused friction with Goldman Sachs, the sources said.

It has been said that the investment bank earned "unusually large fees" underwriting a series of bonds in 2012 and 2013 for the state investment fund. According to CNBC, the biggest bond deal was worth $3bn and earned the bank$300m which is said to be "many times above the standard rate." The typical rate for an investment bank is only about 5%.

The investment bank however has stood by the fees charged, claiming it took risks in bringing the hastily arranged and unrated bonds for $2.7bn and profited by reselling them to investors at a higher price over the following months.

News reports have highlighted the close relationship between Leissner's wife and Najib's wife Rosmah. According to CNBC, Simmons has tweeted pictures of herself and Rosmah, whom she described as "my friend."

This is what money would look like in the future ....according to a tweet in November 2013.

Finance Magnates Executives said: "It is unclear where his [Leissner] next destination is or what the immediate fallout will be after the series of probes [into 1MDB] run their course."