Marc Agnifilo, the lawyer, said that was why his cross-examination of Leissner frequently touched on the banker’s private life.

Ng is accused of conspiring to violate US anti-money-laundering laws in a scheme to loot billions from 1MDB.

“Our premise is that all of the relationships he has, they’re all strategic,” Agnifilo said.

“Leissner was instrumental not just in his capacity as an efficient Goldman Sachs employee, but in having personal connections with people.”

Ng is accused of conspiring with Leissner and Malaysian financier Jho Low in a scheme to bribe officials in Malaysia and Abu Dhabi and loot hundreds of millions of dollars out of 1MDB.

Leissner, who pleaded guilty in 2018, is the government’s star witness against Ng, who he described as maintaining Goldman’s relationships with Ng and others.

But Ng argues Leissner, his former boss, led those relationships.

Agnifilo was arguing to introduce into evidence an email between Leissner and former Astro Malaysia Holdings Bhd chief executive officer Rohana Rozhan. Rohana was also Leissner’s mistress.

“It is relevant in light of Leissner’s testimony that it was Ng who had these ‘critical relationships’ to help these deals move forward,” Agnifilo said.

Leissner “was putting Roger in all of this when Leissner is the one who’s using connections. Sometimes he uses intimacy,” the lawyer said.

The judge said she would consider whether to allow the evidence and would rule later on this.