A woman who held a New Year’s Eve party for more than 100 people faces a £10,000 fine, the Metropolitan Police said.
Officers found the event, in Exhibition Road, Kensington, when they spotted a large group outside trying to get in.
The force said the organiser refused to co-operate with officers, who returned on Monday to notify her that she had been referred for the maximum penalty under coronavirus regulations.
Acting inspector Ganesh Rasaratnam, from the Met’s central west basic command unit, said: “We are in the middle of a pandemic and restrictions have been put in place to keep our families, friends and communities safe.
“The organiser, and those who attended, deliberately breached the restrictions and decided that the rules did not apply to them.”