Minister Chloe Smith has distanced herself from her husband’s comments on Covid-19, which he described as “most likely an outbreak of mental illness”.
Sandy McFadzean also called for an end to social distancing, track and trace and the use of face coverings.
Ms Smith, Conservative MP for Norwich North, said she took a “different view” but felt everyone was “entitled to their own” opinion.
More than 41,000 people in the UK have died of Covid-19, government data says.
The controversy over Mr McFadzean’s comments comes as the the number of daily recorded coronavirus cases is rising.
Government sources also say the testing system is struggling to cope, with some people who show symptoms having to travel more than 100 miles for a swab test.
Mr McFadzean, who is a vice-president of investment bank Credit Suisse, attended last weekend’s march in London against coronavirus restrictions.
He tweeted: “Covid-19 is most likely an outbreak of mental illness.”
A further post read: “Government need to be clear. Either there is a killer virus on the loose or there isn’t. (Spoiler alert: There isn’t).”
Mr McFadzean married Ms Smith, a minister in the Cabinet Office, in 2013.
The MP’s local newspaper, the Eastern Daily Press, which first reported the story, said Mr McFadzean’s Twitter account had been deleted on Wednesday.
Ms Smith told the paper: “My husband’s a private citizen. Everyone’s entitled to their own view, and to debate. I take a different view.”
Ms Smith’s own Twitter account carries the hashtag #stayalertsavelives, an abbreviated version of the government’s coronavirus slogan “Stay alert, control the virus, save lives”.
Credit Suisse declined to comment, but Clive Lewis, Labour MP for Norwich South, said: “There’s absolutely no way I’d hold anyone responsible for the views of their partner.
“However, if my partner was spouting forth Covid conspiracy, anti-vaccination nonsense, it is very likely the subject might come up for discussion at some point over tea.”