However, the cooperation was only about the possibility of money-laundering by a businessman said to have duped 1MDB, he said according to Bernama.

Abu Kassim did not name the businessman. However, documents filed by the US government on Thursday named Penang-born businessman Low Taek Jho (Jho Low) as having used funds linked to 1MDB in the purchases of luxury properties, a private jet, a hotel and several works of art. It alleged that he had laundered the money through a chain of bank accounts.

The suit also names Riza Aziz and two officials of Abu Dhabi-owned companies.

The US government seeks to seize the assets, valued at US$1 billion, under its Kleptocracy Asset Recovery Initiative.

Abu Kassim said the FBI was investigating the activities of a businessman said to have cheated 1MDB and was also involved in laundering money before taking it to the US.

“As such, the US sought our assistance and we only assisted as provided under the United Nations Convention Against Corruption. (Under the convention), agencies are required to give their cooperation and support when confronted with a crime involving several countries,” he told reporters while on a visit to MACC Kelantan.

MACC had confirmed in a statement on Friday that it was cooperating with the FBI in its 1MDB investigations.

The prime minister Najib Razak has said the government took a serious view of the civil suit by the US Department of Justice and would give its full cooperation to all international investigation bodies.