LONDON (Reuters) – The son of Angola’s veteran ex-president faced corruption charges before the country’s supreme court in a trial which opened on Monday, state news agency ANGOP said, the most high-profile case yet under the government’s anti-corruption drive.

Former head of Angola’s $5 billion sovereign wealth fund Jose Filomeno de Sousa dos Santos – nicknamed “Zenu” – along with three other defendants including the former governor of the country’s central bank, are accused of transferring $500 million from the bank to a Credit Suisse account in London.

The charges cite “money laundering, fraud and influence peddling” linked to the funds, which ANGOP said were supposed to be part of a $30 billion strategic investment fund.

The defendants allege that the transfer was authorized by former president Jose Eduardo dos Santos, whose nearly 40-year grip on power in Africa’s second-biggest oil exporter ended in 2017 when he stepped down.

Judges agreed to allow a motion by the defense for the senior Dos Santos, who is abroad for medical treatment, to produce a sworn statement on whether he gave his approval.

Representatives of the Dos Santos family did not immediately respond to a Reuters request for comment. Members of the family have previously denied corruption allegations.

Dos Santos appointed close allies and kin to key positions but his successor Joao Lourenco, also a member of the ruling People’s Movement for the Liberation of Angola (MPLA) party, has rooted out some of his loyalists and initiated a series of graft trials as he pledged to fight corruption.

After taking over in 2017, Lourenco fired Dos Santos’ son as well as his daughter, Isabel, who served as state oil company Sonangol’s chair, and the government has sought to crack down on the influence of the ex-first family, reform bloated state institutions and privatize state firms.

Dos Santos junior was released from six months’ detention in March after authorities said a business partner freed around the same time had returned over $3 billion allegedly purloined from the sovereign wealth fund.

Reporting by Noah Browning; Editing by Emelia Sithole-Matarise