A new report by the consumer watchdog group Public Citizen accuses Amazon of price gouging during the pandemic. According to the group, Amazon increased the prices of essential items like masks, hand sanitizer, disinfectant spray, paper towels and toilet paper.

According to the report, the cost of a 50-pack of disposable face masks jumped from about $4 on April 1st to $39.99 on August 16th. That’s a 900 percent increase. Toilet paper sold by other retailers for $6.89 sold on Amazon for nearly $37, Public Citizen says. In August, the cost of disinfectant spray reportedly increased from about $7 to $13, a jump of more than 80 percent. Even the prices of flour, sugar and cornstarch varied widely.