Scientists advising the Government during the coronavirus pandemic were sent suspicious packages from people who say they are "making bad decisions".
Professor Calum Semple, who sits on the Scientific Advisory Group for Emergencies, spoke out about being on the receiving end of a "particularly nasty" experience.
The professor of child health and outbreak medicine at the University of Liverpool has regularly appeared on television and radio in the past year to be quizzed on the situation with coronavirus in the UK, as have other experts.
He said scientists like himself and others had "attracted adverse attention" during that time.
During a webinar hosted by the Royal Society of Medicine on Thursday, he was asked about the issue.
Professor Roger Kirby, president of the society and host of the session, asked: "You've been targeted by the anti-vax group, haven't you?"
Prof Semple said that was correct and added: "We are fortunate that the police are open to hearing from us and there's good liaison support for us when these threats are made. That was one particularly nasty event.
"There have been others since then and suspicious packages sent to Sage members and myself.
"This comes from both extremes - people that feel that we're making bad decisions and they don't appreciate that Sage is not a decision-making body."
He stressed that scientists advising Government are there to answer "exam questions from ministers or from chief scientific officers or chief medical officers", and to give their best estimates.
He said: "I've never been at a Sage meeting where we've sat around drinking coffee saying 'wouldn't it be a jolly good idea if we closed the pubs?'
"That conversation has never and will never happen.
"It's about what is the likely contribution of construction versus schools versus large matches, and that's where you can then present a menu of likely impacts, and then it's for policymakers to make the decisions, but we're not a talking shop or we're not a suggestion box or a brains trust, it's very much about dealing with inadequate information and giving best opinion."
