The Mad Max star's agent says he was treated with Remdesivir, the anti-viral drug that Donald Trump has bought huge supplies of.
Mel Gibson spent a week in hospital in Los Angeles being treated for coronavirus, it has emerged.
The 64-year-old actor and filmmaker received treatment after contracting COVID-19 in April, his agent confirmed to The Daily Telegraph in Australia.
"He tested positive in April and spent a week in the hospital," the representative said.
"He has tested negative numerous times since then as well as positive for the antibodies."
The agent added that the Braveheart star had been treated with the drug Remdesivir during his hospital stay.
Earlier this month President Donald Trump boasted that the US had bought up almost all of the world's entire supply of the anti-viral drug, which is manufactured in America.
Gibson appears to have made a full recovery from the virus and has been seen out with his girlfriend in Malibu in recent weeks.
Coronavirus continues to surge in many parts of California, with more than 425,600 confirmed cases in the US state.
There were 157 coronavirus deaths in California on Thursday, the highest number reported in the state in a single day.
California Governor Gavin Newsom called it a "grim milestone".
Last month actress Winona Ryder repeated claims that Gibson made antisemitic remarks about her at a party in the 1990s.
She alleges he asked her if she was an "oven dodger" and also made homophobic comments about her friend, the late makeup artist Kevyn Aucoin.
Gibson's representative said the allegations, which date back to "around 1996", were "100% untrue".
In a statement to Variety, Ryder said: "I believe in redemption and forgiveness and hope that Mr Gibson has found a healthy way to deal with his demons, but I am not one of them."
In June, Aardman Animations announced it was teaming up with Netflix to make a sequel to Chicken Run but it is not known if Gibson will reprise his role as Rocky the rooster.