Earlier this month, Khan asked the Johannesburg high court to block the inquiry from accessing electronic devices seized from him when he was arrested. He also wanted his testimony heard behind closed doors but later abandoned both bids.

This is the second time a witness linked to the Madlanga commission has come under attack. In December, a witness was killed in front of his family just three weeks after he gave testimony at the inquiry.

Khan, another senior police officer and a businessman were arrested last month for alleged illegal dealing in, and unlawful possession of, precious metals.

This stems from a 2021 incident when the businessman was found with unwrought gold weighing 75.9g (2.7 oz) at Johannesburg's OR Tambo international airport.

When questioned, the businessman claimed he was acting as an undercover agent for senior police officers.

Investigators later found that "no authorised undercover operation involving precious metals existed at the time" but that Khan, and another officer had "instructed officers" to release the businessman, prosecutors said in May.

He has not yet commented on the allegations but had been freed on bail.

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