"This was a serious and inexcusable error of judgement. Given the restrictions, I realise how irresponsible these actions were and I take full responsibility.
"I feel particularly embarrassed knowing first-hand how hard people have worked to combat this terrible illness and being fully aware of the sacrifices that people and businesses have made to help keep us all safe. Even though this won't make it right, I want to sincerely apologise."
Rita reportedly decided to pay the fine voluntarily to help make up for her mistake.
A source told MailOnline: "Rita knows her actions were wrong which is why she has voluntarily paid the $20,000 fine to the council. She hopes this will go some way to making up for her error of judgement."
Meanwhile, Kensington and Chelsea Council confirmed it intends to investigate the event.
In a statement, the council said: "We are aware of the reports and will be investigating them with the premises."
