Malaysian PM Najib Razak is facing pressure internationally and at home amid US allegations of massive fraud at state investment fund 1MDB.
The fund was set up by Mr Najib in 2009 with the stated aim of boosting the Malaysian economy.
But US Attorney General Loretta Lynch said evidence showed it had defrauded Malaysians "on an enormous scale".
On Wednesday, US authorities moved to seize more than $1bn (£761m) in assets related to the fund.
Mr Najib is not named in the papers and has consistently denied wrongdoing.
But he is identifiable as "Malaysian Official 1", whose account allegedly received millions in funds originating from 1MDB.
The $1bn the US hopes to seize would make up only a proportion of the more than $3.5bn (£2.6bn) allegedly diverted, foreign media reports.