Tests have found no traces of Covid-19 in swabs and air samples of four major railway stations and intercity train services, Network Rail has said.
Two lots of testing took place at London Euston, Birmingham New Street, Liverpool Lime Street and Manchester Piccadilly station.
Heavily touched areas such as escalator handles were swabbed, while hour-long air samples checked for airborne virus.
Tests were repeated on trains running between the stations.
There has been extra cleaning of transport services throughout the pandemic to protect against the virus spreading through contaminated surfaces and the air.
Imperial College London researchers examined the results of the tests – which took place in January and June – and found no coronavirus contamination of any surface or airborne virus particles.