KUALA LUMPUR (THE STAR/ASIA NEWS NETWORK) - Authorities in Abu Dhabi have arrested Khadem Al Qubaisi, whom they say is a key figure in an alleged multibillion-dollar fraud related to a Malaysian sovereign-wealth fund, according to people familiar with the matter, the Wall Street Journal (WSJ) reported.

The WSJ said the arrest last week was made in relation to an Abu Dhabi investigation into fraud and corruption, which includes Qubaisi's alleged role in the 1Malaysia Development Bhd (1MDB). No charges have been filed against him.

The WSJ had in April reported Qubaisi was previously restricted from leaving the United Arab Emirates and had his assets in the country frozen.

However, a lawyer for Qubaisi declined to comment.

WSJ said US investigators were expanding their probe into Qubaisi's dealings and funds they suspect he took control of through the alleged fraud, according to people familiar with the probe.

The Justice Department filed civil lawsuits last month seeking to freeze about US$100 million (S$134 million) of real estate in the US that he allegedly bought with money embezzled from 1MDB, a fund set up in 2009 to boost Malaysia's economy.