These images show three men who ‘seemingly had no legitimate reason’ to be near a peregrine falcon nesting site.
An appeal has been launched after eggs were suspected stolen from the heavily protected nest near the Dutton Viaduct last year.
The trio triggered a trail camera close by in the early hours of May 2, 2016.
Railtrack own the land near the viaduct on the line between Runcorn and Northwich which has no public access.
Peregrines have regularly nested at the site, but attempts have failed for nine years in a row.
A National Wildlife Crime Unit spokesman said: “There is no public right of access and there seems no legitimate reason why these men should be at the location.
“Human interference has been suspected on a number of occasions.
“ Cheshire police and the NWCU would like to speak to the men shown in the images below in order to ascertain whether they have any information relating to the failure of the nest.”
Peregrine falcons, their nests and eggs receive the highest level of protection.
It is an offence to take, kill or injure the bird, take or possess their eggs or to disturb them whilst they are in or near a nest containing eggs or dependent young.
The appeal has been released in response to a mention on the BBC’s Countryfile.
Anybody with any information should contact Cheshire police on 101 quoting incident number 136 of May 4, 2016.
Alternatively information can be given anonymously by contacting Crimestoppers on 0800 555 111.
