KUALA LUMPUR • Malaysian police have questioned the credibility of a New York Times (NYT) report that a United States federal grand jury is investigating allegations of corruption involving Prime Minister Najib Razak and a number of individuals close to him.

Deputy Inspector-General of Police Noor Rashid Ibrahim yesterday said that this was because no foreign authorities had so far approached the Malaysian police over the alleged investigations, according to The Malaysian Insider news website.

Datuk Seri Noor said that if the report were true, the Malaysian police would have been contacted.

"I am not sure if that report is true... I do not know if there is an investigation," he was quoted as saying.

"What I do know is, the foreign authorities have not sought out police here. If there were a probe, then definitely they would have contacted police here, so it is difficult for me to comment further," he told reporters at a function at the federal police headquarters in Bukit Aman.

On Tuesday, NYT reported that a US grand jury was the latest authority to begin investigations into Datuk Seri Najib over US properties purchased by his stepson Riza Aziz and a family friend, businessman Low Taek Jho.

A unit in the US Justice Department that investigates international corruption was conducting the inquiry, NYT quoted anonymous sources as saying.

The inquiry is focused on real estate purchases in the US in recent years by shell companies that belong to Mr Riza as well as other real estate connected to Mr Low, who is also known as Jho Low.

NYT had reported in February about purchases using shell companies by various international figures, including Mr Riza and Mr Low.

On Tuesday, the newspaper said the Justice Department investigation was still in its early days, and that it could take years to determine if any federal laws had been broken.

The report also said that investigators would look into the nearly US$700 million (S$993 million) allegedly deposited into Mr Najib's personal bank accounts, as reported by The Wall Street Journal in early July and later confirmed by the Malaysian anti-graft authorities as a political donation.

The funds transfer comes under US jurisdiction because it went through Wells Fargo, a US bank, NYT said.

In its February report, NYT said more than RM150 million (S$49 million) in properties were traced back to either Mr Low or Mr Riza.

These included a penthouse at the Time Warner Center in Manhattan bought for US$30.55 million by a shell company connected to Mr Low's family trust.

Representatives for the two men told the paper that they had not been involved in any inappropriate business dealings.