HSBC has frozen more than $87m in accounts linked to a Chinese tycoon behind several multibillion-dollar deals in Africa, while it investigates allegations of “serious financial crimes”.

Accounts controlled by Sam Pa and his business associate Veronica Fung were blocked by the bank a year ago, but its internal investigation is still going, court documents have revealed. Last week, a Hong Kong judge declined Mr Pa and Ms Fung’s request that he order HSBC to release the funds, which are “extremely substantial”, according to the ruling. One account alone contains $87m, the documents show Mr Pa has built a network of interests in oil, minerals and infrastructure by cultivating regimes regarded as among the world’s most repressive and corrupt, from Angola to North Korea — often blazing a trail for Chinese state-owned groups. His commercial empire, known as the Queensway Group after the Hong Kong address of its headquarters, has amassed assets including the former JPMorgan building opposite the New York Stock Exchange.

In a 2014 Financial Times investigation, people who have had dealings with Mr Pa — who goes by at least seven different names — claimed he had close ties to the Chinese intelligence services.