Suffolk officer Michael Upson had 649 birds' eggs

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Media captionFormer PC Michael Upson kept detailed records of his egg collection at his home in Suffolk

A Suffolk police constable illegally amassed a collection of 649 rare birds' eggs, a court has heard.

Michael Upson, 52, admitted having the eggs in his possession, contrary to the Wildlife and Countryside Act 1981.

Norwich Magistrates' Court heard the eggs were found at his home in Sotherton, Suffolk during a raid by police officers and RSPB investigators.

Upson, who has since retired, is due to be sentenced on Thursday.

Diary notes were found describing how and where the eggs were found but Upson denied he had collected the eggs while on duty.

'Eggs in gloves'

The diaries found by RSPB officials included notes stating: "Later in the morning I had to pick up a colleague. Whilst idly chatting he happened to mention a car number to look out for - the car contained suspected egg collectors!

"He had seen it on the computer… Little did he know what the gloves in my jacket pocket on the back seat contained!"

Upson kept the eggs in margarine cartons in a battered suitcase.

When questioned by detectives, he initially claimed that they belonged to his father, and had been collected before such activity became illegal.

He showed officers index cards suggesting that the eggs belonged to E G Upson, and that they had been collected in the 1940s.

However, the police and the RSPB were not convinced, and hidden in a water tank in the loft they found a sealed box containing the real cards and the incriminating notebooks.

They also found Suffolk police issue diaries which used a simple code to list the date of the find, the number of eggs and the bird type.

These suggested that numerous times he had collected eggs while on duty - on night shifts and, on one occasion, just after he had been told he had missed out on a promotion to sergeant.

Missed promotion

In his collection, the RSPB discovered many eggs from birds on the most protected "Schedule 1" list, including marsh harriers, warblers and nightjars.

Image caption Michael Upson helped police and the RSPB when they searched his home

He had a particular fondness for wood larks, with dozens of their eggs; yet at the time he was collecting there were fewer than a thousand breeding pairs in the entire country.

Mark Thomas, who led the RSPB investigation, said that for collectors, each egg represented a personal achievement in locating the nest and outsmarting the authorities, so eggs were rarely sold among collectors.

Collectors will usually take the entire clutch of eggs, leaving the birds with nothing.

Following his arrest in June, Upson was suspended but he retired from the police in August before being convicted, and he will keep his pension.

The maximum sentence for collecting wild bird eggs is six months' imprisonment.

Upson's collection will probably be destroyed, although some may be given to museums.