The official advice is to open a window to increase ventilation and slow the spread of Covid, but now there could be an added incentive – the virus may also be spread by flatulence.
Ministers have privately pointed to evidence that Covid could be spread by people breaking wind in confined spaces such as lavatories. One said they had read "credible-looking stuff on it" from other countries, although government scientists are yet to produce a paper on the matter.
The source said there had been evidence of a "genomical-linked tracing connection between two individuals from a [lavatory] cubicle in Australia."
There were also "well-documented cases of diseases spreading through waste pipes during lockdowns in Hong Kong when the U-bend had dried out".
The science is not definitive, however, and another minister told The Telegraph that as Covid is "a respiratory disease, transmission and shedding is mostly taking place through the mouth and actually mainly the nose".