A scientist whose research aided Prime Minister Boris Johnson's decision to impose a lockdown has resigned from the UK government's Scientific Advisory Group for Emergencies (Sage) after admitting an "error of judgment".
Professor Neil Ferguson said he regretted "undermining" the continued need for social distancing to tackle coronavirus after it was claimed he broke the rules.
The 'Daily Telegraph' reported he allowed a woman to visit him at home in London on at least two occasions during the lockdown.
Prof Ferguson's research with Imperial College London colleagues warned that 250,000 people could die in the UK without drastic action before Mr Johnson imposed the restrictions.
"I accept I made an error of judgment and took the wrong course of action. I have therefore stepped back from my involvement in Sage," Prof Ferguson told the 'Telegraph'.
"I acted in the belief that I was immune, having tested positive for coronavirus, and completely isolated myself for almost two weeks after developing symptoms.