HONG KONG - A French biosecurity expert who supervised the construction and accreditation of the biosafety level 4 (BSL-4) laboratory of the Wuhan Institute of Virology (WIV) has dismissed the theory that COVID-19 escaped from the lab, a Hong Kong newspaper reported Friday.

The French expert, Gabriel Gras, put the chance of a leak from the BSL-4 laboratory at "zero percent", according to the South China Morning Post.

"The lab is of a high standard. It was my daily work to verify this, and as I had the background of safety (consultant), lab designer, and virology scientist, I was 100 percent involved," Gras said, stressing that he had "no doubt" about the safety of the lab.

According to the report, Gras also had little doubt that the virus is natural.

"I am 100 percent sure it is not constructed, developed in a lab," he said.

The virology researcher pointed out that the discussion about the pandemic's origin had become politicized. "For me this is (no longer) a scientific issue."