Malaysia is investigating how former Goldman Sachs Group Inc. banker Roger Ng raised billions of dollars in bonds for sovereign state fund 1MDB, according to the police.

Malaysia’s police are counting on Ng’s cooperation to recover as much as possible from the billions of dollars looted from the 1MDB sovereign wealth fund in the previous decade. Ng, a Malaysian, is under police protection after arriving from the US on Sunday, Inspector General of Police Razarudin Husain said on Tuesday.

“We hope that he will cooperate on the asset recovery,” Razarudin told reporters. “There is a lot of assets to be returned.”

Goldman made $593 million working on three bond sales that raised $6.5 billion for 1MDB in 2012 and 2013. Under a July 2020 settlement, Malaysia dropped all criminal charges against the bank over its role in the scandal in exchange for a $2.5 billion cash payment and for the guaranteed return of $1.4 billion of seized 1MDB assets.

Ng was convicted in the US in connection with 1MDB, and was scheduled to begin a 10-year prison sentence on Oct. 6. But US officials allowed the sentence to be deferred so that Ng could return to Malaysia and assist the investigation.