The Swiss authorities, acting on United States request, have seized three rare paintings linked to an investigation into the scandal-hit Malaysian state fund 1MDB.
A spokeswoman for the Federal Office of Justice said the paintings were Vincent van Gogh's La maison de Vincent à Arles and Claude Monet's Saint-Georges Majeur and Nympheas avec Reflets de Hautes Herbes. She was confirming a report by the Neue Luzerner Zeitung newspaper.
"The operation is not over yet so we will not comment at the moment on the location of the paintings," she said.
The US government on Wednesday filed lawsuits seeking to seize $1 billion in assets bought with money believed to have been stolen from the Malaysian 1MDB sovereign wealth fund.
The civil lawsuits allege that a total of $3.5 billion was misappropriated from 1MDB, a fund Malaysian Prime Minister Najib Razak established in 2009 and whose advisory board he chaired.
Federal prosecutors are seeking to seize $1 billion that they say was diverted from 1MDB into luxury real estate in New York, Beverly Hills and London as well as paintings by Van Gogh and Monet and a private jet.
They also are trying to seize proceeds from the 2013 film "The Wolf of Wall Street". Riza Aziz, Najib's stepson and founder of Red Granite Pictures, which produced the movie, was named in the lawsuit.
On Wednesday the Office of the Swiss Attorney General confirmed that it was cooperating with the United States Department of Justice (DoJ).
The lawsuits filed on Wednesday did not name Najib, instead referring to "Malaysian Official 1." Some of the allegations against this official were the same as those contained in a Malaysian investigation into a $681 million transfer to the premier's personal bank account.
The lawsuits said $681 million from a 2013 bond sale by sovereign wealth fund 1Malaysia Development Berhad (1MDB) was transferred to the account of "Malaysian Official 1".
Najib, who has consistently denied any wrongdoing, said on Thursday the US lawsuits were "a civil not a criminal procedure".
Najib said the government would give its full cooperation to international investigations of the 1MDB case.
swissinfo.ch with agencies