By Stephen Eisenhammer

LUANDA (Reuters) – Angola’s sovereign wealth fund has applied to a UK court to order banks to reveal information, another move in its dispute with its former boss, the son of long-serving ex-leader Jose Eduardo dos Santos, and the asset managers hired under him.

President Joao Lourenco, who took over when dos Santos stepped down last year after nearly 40 years in power, has swiftly moved to push aside relatives and allies of dos Santos from positions of power and influence over the economy.

The $5 billion (3.7 billion pounds) sovereign wealth fund has been embroiled in a dispute with its former boss, the ex-president’s son Jose Filomeno dos Santos, and the Swiss-based asset manager contracted to invest money for the fund, Quantum Global.

The fund is trying to sack the fund manager, accusing it of mismanagement. Quantum Global denies wrongdoing and says the fund has violated its long-term contractual obligations.

A source directly familiar with the matter told Reuters the sovereign wealth fund had sought a so-called “Norwich Pharmacal order” to oblige banks to share information with the fund, including data about any accounts held in its name or on its behalf.

Such orders, named for a legal case from the 1970s, can be used in British court to force third parties to reveal information.

A hearing was held earlier this month at the Rolls Building, a tribunal in London which deals with international disputes, a separate source said.

Lourenco has vowed to fight graft after taking power last September and has moved against the family of the previous president, firing dos Santos’s daughter Isabel from her post as head of the state oil firm Sonangol as well as removing Jose Filomeno from the sovereign wealth fund.

In a separate case, Jose Filomeno dos Santos has been accused by Angolan prosecutors of participating in an attempted fraud of $500 million against the central bank. He denies wrongdoing.

The sovereign wealth fund has already been granted a global freezing order by a UK court covering funds held under its name or by contracted parties.

Quantum Global, which is led by Jean-Claude Bastos de Morais, a long-term business partner of Jose Filomeno dos Santos, has denounced what it calls “intimidating tactics,” saying the money it has under management is accounted for and “has increased under Quantum Global’s management”.

In a press release dated 11 May, Quantum Global confirmed the sovereign wealth fund had started legal proceedings against it in the UK High Court and that a freezing order had been granted, without giving further details.

On Wednesday, Quantum Global did not immediately provide any additional comment. The sovereign wealth fund did not immediately respond to a request for comment.

Last month, after a visit by Angolan officials, Mauritius froze bank accounts and suspended business licences linked to QG Investments Africa Management, a firm run by Bastos de Morais and which also invested money on behalf of the sovereign wealth fund.

(Reporting by Stephen Eisenhammer; Editing by Peter Graff)