A programme designed to track where Covid-19 variants are circulating has discovered traces of the virus in various Norfolk sewers.
Since 2020, the UK Health Security Agency has been monitoring wastewater across the country to help assess the spread of the coronavirus.
The programme works on the knowledge that people infected with Covid-19 shed the virus when they go to the toilet and blow their nose, causing it to enter the sewer system through sinks, drains and toilets.
Sewer systems being tested for the virus locally include Norwich, Great Yarmouth, King's Lynn, Reepham and Cromer.
The tests have been ongoing as a means of gauging where outbreaks have occurred that may not have been picked up by clinical testing programmes.
And the latest set of results published have shed more light on how the Omicron variant spread through the county over the course of December and January.
The most recent results made available were based on testing carried out between December 27 and January 2.
And these found confirmed cases of the Omicron variant of the virus in sewage treatment plants in Cromer, Norwich, Great Yarmouth, Lowestoft, Thetford, Diss, Downham Market and Dereham.
Testing of sewage treatment plants in Wells-next-the-Sea, Hunstanton, Reepham, King's Lynn, Wisbech and Beccles did not detect any traces.