An indebted Malaysian state investment fund says it will cooperate with Swiss prosecutors whose investigation indicated that $4 billion may have been misappropriated from Malaysian state-owned companies.

The top Swiss prosecutor says he has sought Malaysia's help after the probe into 1MDB confirmed that a small amount of that money was transferred to accounts held in Switzerland including by a former Malaysian public official.

Prime Minister Najib Razak, who formed 1MDB in 2009, became embroiled in the scandal after documents leaked last year suggested some $700 million deposited into his accounts may have come from entities linked to 1MDB. Malaysia's attorney-general has cleared Najib of any wrongdoing, saying it was a private donation.

1MDB said Saturday it hasn't been contacted by any foreign agency but it is willing to cooperate.