UAE authorities have arrested Khadem al-Qubaisi, former managing director of Abu Dhabis International Petroleum Development Company (Ipic).
The arrest is said to be related to a US investigation into billions of dollars defrauded from Malaysian sovereign wealth fund 1MDB, according to reports by the the US Wall Street Journal and the UKs Financial Times.
Al-Qubaisi stepped down from Ipic in 2015, and has had his UAE accounts frozen.
The suit filed by the US Department of Justice alleges $3.5bn was misappropriated from 1MDB, and that the proceeds were partially laundered in the US. Al-Qubaisi allegedly received about $470m of this money.
Ipic is pursuing a separate $6.5bn arbitration against 1MDB in London. It is seeking the return of billions of dollars, allegedly misdirected to companies in the Cayman Islands with similar names to Ipic subsidiaries.
In 2015, Ipic bailed out the debt-laden 1MDB by agreeing to provide it with $1bn in cash and to assume $3.5bn of 1MDB debt in exchange for some of the funds assets. It alleges that payments related to the guarantees were never received.
1MDB denies all wrongdoing, but is cooperating with the US investigation.
Abu Dhabi plans to merge Ipic with its Mubadala Development Company.