Chris Whitty has condemned US rapper Nicki Minaj for her tweets about Covid jabs, saying she should be “ashamed” of her anti-vax message.

The chief medical officer for England looked visibly angry as he was asked about the singer’s comments at a joint press conference with Boris Johnson.

Minaj, who has over 22 million followers on Twitter, had posted: “My cousin in Trinidad won’t get the vaccine cause his friend got it and became impotent. His testicles became swollen.

“His friend was weeks away from getting married, now the girl called off the wedding. So just pray on it and make sure you’re comfortable with your decision, not bullied.”

Prof Whitty used the Downing Street briefing to hit back at claims like the ones Minaj made. He called Minaj’s claims “false” and said those who discourage others from getting the vaccine “should be ashamed”.

He said: “There are a number of myths that fly around... some of which are just clearly ridiculous and some of which are clearly designed just to scare. That happens to be one of them. That is untrue.”

Mr Johnson added: “I am not as familiar with the works of Nicki Minaj as I am with the works of Nikki Kanani, superstar GP of Bexley [medical director of primary care for NHS England], who will tell you vaccines are wonderful.”

Prof Whitty went on to say anti-vaxxers “are a group of people who’ve got strange beliefs… and they make their own choices”.

He added that while most people ignore the conspiracy theories, they are peddled by people who “intend to scare”.

Minaj was widely criticised for her tweets about the Covid vaccine, which has no proven link to fertility problems.

The singer remains unvaccinated but told her followers she would probably receive the jab so she would be able to tour.