A former policeman yesterday admitted illegally possessing 650 wild bird eggs collected while he was still a serving officer, the RSPB said.
A search of Michael Upson's house in Suffolk revealed 650 wild bird eggs, including those of protected species such as Cetti's warbler believed to be from the Westcountry, woodlark and marsh harrier, the charity said.
Upson, 52, pleaded guilty to possessing the eggs at Norwich Magistrates' Court following a joint investigation by his old force Suffolk Police, Norfolk Police and the RSPB.
Notebooks found at the house documented Upson's egg-collecting trips with others around the UK.
On one occasion they showed he took kittiwake eggs from Lowestoft Pier while on duty as acting sergeant on three different night shifts for Suffolk Police.
The notebooks also detailed visits to South Devon to take Cetti's warbler eggs, the Western Isles to steal golden eagle eggs, North Wales to steal chough eggs, and the New Forest to take hawfinch eggs, the charity said.
Upson claimed to have stopped egg collecting, and the evidence found indicates that he was active between at least 1991 and 2001, the charity said.
Upson, from Sotherton, Suffolk, will be sentenced at Norwich Magistrates' Court today.