A health worker checks a blood sample for malaria at a hospital in Pailin province. Photograph: Reuters

The head of a unit which has been investigating the Cambodian government's National Malaria Center on behalf of the country's largest healthcare donor was sacked Thursday for "unsatisfactory performance."

John Parsons, the inspector general for the Global Fund to Fight AIDS, Tuberculosis and Malaria, was fired by the $23 billion fund following a thorough review of his work, the organisation's board wrote in a statement issued Thursday.

Though the specific reasons for his dismissal have yet to be publicised, Parson's firing was slammed by the world's largest HIV/AIDS organization, which accused the Global Fund of likely "being uncomfortable having its shortcomings so exposed,” according to Tom Myers, AIDS Healthcare Foundation's general counsel.

Parsons had oversight of the Office of the Inspector General – which for the last 18 months has been investigating the fund's Cambodia programs amid allegations of corruption. Earlier this week, the Global Fund revealed it had found evidence of significant financial wrongdoing and announced it would no longer be funneling money directly through the Cambodian government's malaria center.

A report on the Global Fund findings is expected in a matter of weeks and a spokesman on Friday insisted that despite qualms surrounding Parsons' abilities, the quality of the Cambodian investigation had not been compromised in any manner.

"The Board's decision to dismiss him does not invalidate or interrupt ongoing investigations. It will not affect the forthcoming report," said communications department head Seth Faison.

According to sources with knowledge of the investigation, the fund had uncovered significant corruption within the National Malaria Center. In an internal report of the findings thus far, the fund late last month warned that the Center's mismanagement had caused risks to the medication supply and finances.

Ministry of Interior spokesman Khieu Sopheak said Friday he was not aware of a pending investigation into the Center, and referred questions to the government's anti-corruption watchdog. Multiple calls to Anti-Corruption Unit director Om Yentieng and his spokesman Keo Remy went unanswered Friday.

To contact the reporter on this story: Abby Seiff at [email protected] ; David Boyle at [email protected]

With assistance from Khouth Sophak Chakrya