ZURICH (REUTERS) - Switzerland's federal prosecutor said on Tuesday that Malaysia had agreed to arrange for Swiss investigators to interview witnesses in their investigation of alleged corruption and money laundering related to the Malaysian state-owned fund 1Malaysia Development Berhad (1MDB).

In a statement, Switzerland's Office of Attorney General said that its chief, Michael Lauber, met on Tuesday with his Malaysian counterpart, Tan Sri Dato Sri Mohamed Apandi Ali, to discuss "mutual cooperation" in the 1MDB case.

The statement said that the Swiss regarded Malaysian cooperation as crucial to their ongoing inquiry.

Mr Lauber is currently hosting a meeting in Zurich of the International Prosecutors' Association.

The Swiss did not identify witnesses whose testimony they formally requested Malaysian authorities to arrange.

Mr Lauber's office said that it had already frozen assets "amounting to several tens of millions of US-dollars" in Swiss bank accounts in connection with its probe.

It also said that on Aug 14, it had opened criminal proceedings against two 1MDB officials and other unknown persons for corruption and suspected money laundering.

Investigations are based on two notifications of suspicious transactions flagged by Switzerland's anti-money laundering agency.