The MACC's investigation into 1MDB is 60 percent complete, said deputy chief commissioner (operations) Azam Baki.
He said local investigations were almost complete and the commission must now scrutinise evidence secured from abroad.
Azam told a press conference in Putrajaya today that more time was needed to complete the probe because gathering of evidence involved many countries and investigations were only reopened a few months ago.
"Among the countries that we have to look at as part of the investigation are the United States and Singapore," he said.
The Monetary Authority of Singapore has taken punitive action against several bankers who were involved in 1MDB-related transactions over the past two years.
Among others, Singapore jailed BSI banker Yeo Jia Wei, 35, over money laundering, cheating and witness tampering charges.
Meanwhile, in the US Department of Justice (DOJ) has been actively pursuing 1MDB-related assets which were allegedly misappropriated from 1MDB.
Although no criminal charges had been laid, the DOJ had succeeded in seizing jewellery, artworks and real estate, among other assets.