Najib Razak, the former Malaysian Prime Minister, was arrested at his house in Kuala Lumpur on Tuesday.
During raids on properties linked to Najib and Rosmah Mansor after the election, police seized over 400 handbags and a huge stash of jewels and cash.
Founded by Mr Najib in 2009, 1MDB is being investigated in at least six countries for alleged money laundering and corruption.
The US Department of Justice (DoJ) had claimed that Riza's company, which produced the Oscar-nominated "The Wolf of Wall Street", received money misappropriated from 1MDB.
Former Malaysian prime minister Najib Razak has been arrested by anti-graft officials. The new Attorney-General Mohamed Apandi Ali cleared Najib in 2016, saying the money was a donation from the Saudi royal family and that most of it was returned.
He has denied any wrongdoing.
Najib's arrest comes almost two months after his coalition's stunning rejection by voters in a May 9 general election.
The anti-corruption agency earlier Tuesday questioned Riza Aziz, Najib's stepson and a Hollywood film producer, as it stepped up its probe of 1MDB.
Billions of dollars are unaccounted for from the fund, set up by Mr Najib.
Riza is the co-founder of Red Granite Pictures, a company that USA prosecutors say financed three Hollywood films, including the 2013 Martin Scorsese movie "The Wolf of Wall Street", with funds misappropriated by 1MDB.
MACC chief commissioner Datuk Seri Mohd Shukri Abdull said on May 22 that the MACC probe in 2015 against Najib involved funds of RM2.6 billion and RM42 million that were believed to have been transferred from SRC International to the former prime minister's personal bank accounts.
U.S. investigators say Riza's company, Red Granite Pictures, used money stolen from 1MDB to finance Hollywood films including the Martin Scorsese-directed The Wolf of Wall Street.