Officials from the United States Department of Justice cannot question individuals in Malaysia without the presence of local police officers.
Inspector-general of police Khalid Abu Bakar told Malaysiakini this when asked to respond to a Reuters report on the matter.
Khalid also disclosed that Bukit Aman has yet to receive a notification for assistance from the Department of Justice.
"As mentioned earlier, they must inform us if they wish to question anyone in Malaysia. That is the procedure.
"So far we have yet to be informed about anything regarding questioning people in relation to their 1MDB probe," he added.
Officials from the US Justice Department travelled to Malaysia to meet several individuals in their investigation into 1MDB, according to the Reuters report today which cited unnamed sources.
It is not clear how long the US officials have been in Kuala Lumpur or if they have left, Reuters said, quoting sources who cannot be identified as they are not authorised to speak to the media.
A team of lawyers for Deutsche Bank are also in the capital city to prepare a report to submit to the Department of Justice, one of the sources told the newswire.
Malaysiakini has contacted the US Justice Department for confirmation.
Prime Minister and Finance Minister Najib Abdul Razak is chairperson of the board of advisers of 1MDB – a fully-owned government investment firm established in 2009.
The US investigation comes as international media reports state US$1 billion was deposited into Najib’s personal bank accounts, of which at least US$15 million was spent on luxury goods and holidays.
Deustche Bank had loaned 1MDB US$975 million in 2014, which was repaid last year.
It also advised the fund on a proposed US$3 billion initial public offering for its energy assets, which were instead sold off last month.
The US government is also looking at investment banks JP Morgan and Goldman Sachs in its 1MDB probe.