No traces of Covid-19 found in trains or railway stations
The testing was carried out by Network Rail.
Swabs and air samples taken at four of England's biggest railways stations have found no trace of Covid-19.
Heavily-touched areas such as escalator handles were swabbed and air samples taken at London Euston, Birmingham New Street, Liverpool Lime Street and Manchester Piccadilly in two sets of testing that took place in January and June.
Tests were then repeated on trains running between the stations.
The results were examined by researchers at Imperial College London and found no coronavirus contamination of any surface or airborne virus particles.
The findings follow similar tests taking place on London's public transport systems, which also found no sign of Covid-19 or new variants.
Since the beginning of the pandemic, there has been extra cleaning of transport services across the country to protect against coronavirus, and it seems like these measures are having an impact.
David Green, senior research fellow at Imperial College London, said that the research and tests provided a "way of quantifying the amount of virus circulating in these public environments and the effect of mitigation strategies like cleaning and wearing face coverings."
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Rob Mole, senior programme manager for Network Rail's response to the pandemic, labelled the findings as "proof" that the "dedicated approach" taken by staff at stations was paying off, adding that staff would continue "doing our part by rigorously cleaning trains and stations."
He asked passengers to "do their bit" by continuing to wear face masks while travelling.
Last month, almost all remaining Covid-19 restrictions were lifted, including the legal requirement to wear a face covering in crowded places such as shops and public transport.
However, Sadiq Khan has since announced that face masks will remain compulsory on London's public transport, with the government and health experts still advising that they are worn in crowded and enclosed spaces.