The number of cases in the US has rocketed in recent weeks.
Move raises fears he would use a sentencing hearing next month to promote his white-supremacist views.
Despite the controversy over his death, the Seoul City government organised a five-day funeral for Park.
Benjamin Keough was found in Calabasas near Los Angeles from a self-inflicted gunshot wound.
Covid-19 has now claimed more than 550,000 lives across the planet.