The President of Mozambique has won a High Court immunity fight in London.

President Filipe Nyusi had become embroiled in commercial litigation involving allegations of fraud.

He had claimed immunity “from the jurisdiction” of the High Court of England and Wales because he was a serving head of state – and a judge has ruled in his favour.

Mr Justice Robin Knowles has concluded that “in relation to the claims alleged against him” in the litigation, President Nyusi had immunity “from the jurisdiction of this court” while he was “Head of State of Mozambique”.

He outlined his conclusions in a written ruling released on Monday after considering legal arguments at a High Court hearing in London in August.

The judge has been told how the Republic of Mozambique has alleged that it has been a victim of fraud concerning the supply of “various vessels and maritime systems” – and taken legal action against various defendants, including the Credit Suisse International bank and Privinvest Shipbuilding.

He said in a written ruling that Privinvest had made claims against President Nyusi – and a trial was due to begin in October.

“The litigation concerns a number of transactions or alleged transactions, including alleged purchase and financing transactions,” he said.

“The claims by the Privinvest Defendants against President Nyusi are for a contribution as an alleged joint tortfeasor or a party to an alleged unlawful means conspiracy and in deceit, under Mozambican or English Law,” he said.

“The claims are concerned with alleged activity by President Nyusi outside the United Kingdom, at least primarily before he became president, and in any event not in his public capacity or part of his official functions.”

He added: “The president has responded by claiming immunity from the jurisdiction of this court as a serving head of state.”

The judge said he had considered the terms of the 1978 Sovereign Immunity Act and concluded that “in relation to the claims alleged against him in these proceedings” President Nyusi had “immunity from the jurisdiction of this Court whilst he is Head of State of the Republic”.