Leissner became the firm’s local head of investment banking a few months later. The banker, whose father was a Volkswagen AG executive in Yugoslavia during the Bosnian War before stints in Mexico and China, graduated from Germany’s University of Siegen and got an MBA from the University of Hartford in Connecticut in 1992.

At a 2001 gathering of young Asian leaders, the program listed him as Dr. Leissner for his workshop “What would happen had Einstein joined Wall Street?” A biography he provided at another forum said he got a doctorate in business administration from Somerset University. A school with that name offered degrees for $995, a retired federal investigator told a U.S. congressional committee on education in 2004.

Malaysian Billionaires

Leissner’s contacts were more impressive. In May 2006, he was sitting onstage when the conglomerate controlled by billionaire Syed Mokhtar Al-Bukhary announced its takeover of power producer Malakoff Bhd., what it called “the largest acquisition ever undertaken in Malaysia.” Goldman Sachs was an adviser on the deal. That year, Leissner made partner.

The firm helped manage billionaire T. Ananda Krishnan’s 2009 initial public offering of Maxis Bhd., Malaysia’s biggest wireless operator. Krishnan also controlled Astro Malaysia Holdings Bhd., the largest pay-TV broadcaster, and Goldman Sachs was there when it went public, too.

Leissner was open about his ambition. The firm wanted to do more business in Malaysia, he said in an interview carried by a government news agency. That was before Najib became prime minister in 2009. By the end of that year, the nation’s securities commission cited the new leader’s “strategic shift” when it announced that Goldman’s application to start operations for fund management and corporate finance was approved.

That smoothed the way for the firm’s blockbuster deals with 1MDB, which began as an investment fund set up by oil-rich Terengganu state before Najib took it over. The government-owned entity attracted attention even in early days: Jho Low, a young dealmaker who advised the Terengganu Investment Authority and was a friend of Najib’s stepson, film producer Riza Aziz, popped up in tabloids celebrating in New York and St.-Tropez with Lindsay Lohan, Paris Hilton and magnums of champagne.

Goldman Sachs, where Jho Low’s brother Szen had worked, hit it big, too. The firm made $593 million working on three bond sales that raised $6.5 billion for 1MDB in 2012 and 2013, according to a person with knowledge of the matter, dwarfing what banks typically make from government deals. Leissner was an adviser to the state fund from early on, according to a former colleague familiar with the bond sales.

“There’s no law against bankers meeting with heads of state,” Wong Chen, an opposition member of Malaysia’s parliament, said in an interview this month about Goldman Sachs’s relationship with 1MDB. “That’s a bit too cozy, a bit too overly generous.”

‘Large Requirements’