Malaysia's scandal-hit state fund 1Malaysia Development Berhad (1MDB) has filed a lawsuit against a top PetroSaudi International executive seeking the return of $1.83 billion invested in a joint venture, state news agency Bernama reported on Thursday.

The fund entered what would ultimately become a failed joint venture with PetroSaudi to develop oil fields in 2009.

In a May 7 court filing to the Kuala Lumpur High Court, 1MDB alleged that PetroSaudi Chief Investment Officer Patrick Mahony aided several individuals, including former Malaysian Prime Minister Najib Razak and fugitive financier Jho Low, to misappropriate its funds.

1MDB also named UK-based law firm White & Case LLP as a defendant in the suit, claiming that it acted on Mahony's instructions to prepare purchase and loan agreements on behalf of PetroSaudi to deceive 1MDB, Bernama reported.

Reuters was unable to reach Mahony for comment. White & Case did not immediately respond to a request for comment.

The state fund is seeking for Mahony and White & Case to repay the $1.83 billion to it, among other damages.

Lim Chee Wee Partnership, the Malaysian law firm representing 1MDB, confirmed the filing to Reuters.

Malaysian and U.S. investigators estimate $4.5 billion was siphoned away, opens new tab from 1MDB following its inception in 2009, implicating Najib Razak, Goldman Sachs (GS.N), opens new tab staff and high-level officials elsewhere.