Malaysia’s disgraced state investment fund 1MDB is suing Deutsche Bank, Coutts and JPMorgan, and more than 20 individuals including Malaysia’s former prime minister in an effort to recover more than $23bn in losses the country said it incurred in its largest corruption scandal.

Malaysia’s finance ministry on Monday said 1MDB and subsidiary SRC International filed the suits on May 7 for claims including fraudulent breach of duties, conspiracy and breach of trust.

“1MDB and SRC contend that these entities and/or individuals have been unjustly enriched by wrongfully receiving monies from 1MDB or SRC,” the ministry added.

Deutsche Bank, JPMorgan Switzerland and Coutts & Co are among the companies hit by the lawsuits, according to two people familiar with the matter. Najib Razak — former prime minister and founder of 1MDB — and Jho Low — the Malaysian financier accused of masterminding the embezzlement scandal — are also being sued, they added.

The lawsuits form part of the government’s efforts to recover losses linked to the fund, which was set up to accelerate the country’s economic development but which US and Malaysian authorities allege was plundered to buy luxury real estate, artwork and expensive jewellery.

The scandal uncovered a global web of corruption and shocked Malaysia’s political establishment, resulting in the toppling of its former government whose party had been in power for six decades.

The banks were being sued due to their alleged role as “conduits” for 1MDB, said one person involved in the lawsuits. They became embroiled in the scandal after providing the fund services that included transferring and raising billions of dollars. The claims against them include negligence, breach of contract, conspiracy to defraud and dishonest assistance.

Deutsche Bank said it had “not been served any papers” and was unaware of “any basis for a legitimate claim against” it. The lender said it was misled by 1MDB and that it had co-operated with authorities. Coutts and JPMorgan declined to comment.

In 2019, it emerged the US Department of Justice was investigating Deutsche Bank over its work for 1MDB.

Representatives for Najib and Low — who remains at large and denies wrongdoing — did not immediately respond to requests for comment.

A person with direct knowledge of the matter said filings were made as Malaysia was about to hit a statute of limitations almost three years after a change in government, when Najib was ousted by former prime minister Mahathir Mohamad in 2018.

The filings come after Goldman Sachs last July struck a $3.9bn settlement with Malaysia over its role in the corruption scheme. It had been accused of misleading investors when it helped raise $6.5bn for 1MDB in three bond sales in 2012 and 2013.

More recently, Deloitte in March struck an $80m settlement with Kuala Lumpur over its role as an auditor to 1MDB a week after Malaysian lender AmBank reached a RM2.83bn ($700m) settlement with the government. The bank was dragged into the scandal after Najib was accused of receiving illicit transfers from SRC into his personal accounts at AmBank.

Najib has been sentenced to 12 years in jail after a trial linked to these transfers and faces three more trials involving 1MDB and other government entities. He is appealing against the sentence.