LONDON • The stepson of Prime Minister Najib Razak bought a £23.25 million (S$47 million) four-storey house in London with money from a Malaysian state investment fund, the Wall Street Journal (WSJ) alleged yesterday, citing people familiar with the situation.

And meanwhile, investigators are looking into funds sent to former senior Goldman Sachs Group banker Tim Leissner from a lawyer with ties to the state fund, 1Malaysia Development Bhd (1MDB), the US business newspaper said in a separate report.

The central London house, bought in 2012 by Mr Riza Aziz, is a short walk from Malaysia's diplomatic mission in London's exclusive Belgravia neighbourhood, WSJ said.

The registered owner of the house is Qentas Holdings Ltd, a company based in the British Virgin Islands. Mr Najib's stepson is the beneficial owner, the report said, quoting unnamed people familiar with the issue.

Mr Riza Aziz is the son of Datuk Seri Najib's wife Rosmah Mansor from a previous marriage.

WSJ had in previous reports alleged that Mr Riza Aziz used money channelled from 1MDB to buy US$50 million (S$69 million) worth of properties in New York and Los Angeles and to finance the 2013 movie The Wolf Of Wall Street.

The newspaper quoted a spokesman for Mr Riza Aziz's film company, Red Granite Pictures, as saying last week that the company "is responding to all inquiries and cooperating fully".

"There has never been anything inappropriate about any of Red Granite Pictures or Riza Aziz's business activities," the spokesman said.

"What they have done and will continue to do is develop and produce successful and acclaimed movies that have generated more than US$825 million in worldwide box-office revenues."

Meanwhile, investigators are probing some funds received by Mr Leissner, who was Goldman's South-east Asia chairman until earlier this year.

He received several hundred thousand dollars from Ms Jasmine Loo, a former 1MDB official and a close associate of Mr Low Taek Jho, a Malaysian businessman who played a central role in setting up the fund, WSJ said, quoting people familiar with the matter.

A person familiar with Ms Loo's arrangement with Mr Leissner said they invested together in a start-up company and the deal was structured so that cash for the investment went to Mr Leissner from Ms Loo, the paper reported.