A wake-up call has been given to East Anglian estates after a former north Norfolk gamekeeper was given a suspended jail sentence for poisoning birds of prey.

Allen Lambert, formerly a gamekeeper on the Stody Estate, near Holt, appeared at Norwich Magistrates' Court yesterday for sentencing after being found guilty at trial last month of two charges of killing 10 buzzards and a sparrowhawk, and possession of pesticides and other items capable of being used to prepare poison baits.

The 65-year-old had earlier pleaded guilty to five other charges includes three offences of illegal storage and use of pesticides and unlawful possession of nine dead buzzards.

Lambert, from Holt Road, Edgefield, was sentenced to 10 weeks' imprisonment, suspended for 12 months, ordered to pay costs of £930 and a victim surcharge of £80.

The court heard that Lambert had not been sufficiently supervised in his job as gamekeeper, and his motivation had probably been to protect the birds the estate bred for its shoot.

In sentencing him, district judge Peter Veits criticised the running of shooting estates, and said: 'Those who employ gamekeepers have a strict duty to know what is being done in their name and on their property.

'They also have a duty to ensure their gamekeepers are properly trained and capable of keeping abreast of the complex laws relating to the use of poisons. 'In other industries employers as well as the employee could be facing prosecution in such cases and I hope therefore that this case can serve as a wake-up call to all who run estates as to their duties.'

The Stody Estate did not wish to comment, but in his mitigation, John Hughes said that it was 'shocked and saddened' by the case.

He added: 'Mr Lambert was not authorised or asked to kill any protected wildlife. The estate considered him to be a valued and trusted member of staff.'

For Lambert, Mr Hughes said that he had lost his job, accommodation and good name because of the incident.

'He was well-respected and used to talk to local schools about country crime. He worked hard for the estate, and often for long hours,' he added.

He also said Lambert suffered from rheumatoid arthritis, high blood pressure and had been in poor health since suffering a stroke three years ago.

Animal rights campaigners carrying placards greeted Lambert when he left court.

Joanne Robins, from Norfolk Safe, said: 'I think it's a great disappointment. He should have been sent to prison.'

An investigation was launched in April 2013 by Norfolk Constabulary, assisted by the National Wildlife Crime Unit, Natural England and the RSPB, when quantities of unlawfully held pesticides along with a number of dead buzzards were discovered on the Stody estate.

DC Richard Moden, from Norfolk Constabulary, said: 'Lambert has shown a total disregard for the laws surrounding the protection of wildlife and possession of banned poisons and pesticides.

'Norfolk Constabulary will not tolerate such behaviour, which affects many of us who live and work in the county.'

Lambert was arrested and later charged in December 2013 with seven wildlife offences committed between January 1 and April 4, 2013.

Alan Roberts, investigative support officer for the National Wildlife Crime Unit, said: 'This case has been significant because of the number of birds of prey found poisoned which, together with the lax attitude to firearms security, has exposed an ingrained blasé attitude to lethal chemicals and weapons.'

Guy Shorrock, a senior investigations officer with the RSPB, said: 'I've been investigating wildlife crime for over 20 years and this is one of the worst cases I have dealt with. Finding the carcasses of nine poisoned buzzards in a bag at Lambert's home was truly dreadful. Unfortunately, this is part of a wider national problem and we are calling on the government to bring in stronger legislation to make sporting estates more accountable for the actions of their staff.'

A Natural England spokesman added that they hoped the sentence would prove a deterrent to others.

A spokesman for the National Gamekeepers' Organisation added: 'The NGO stands for game keeping within the law. But the selfish, stupid actions of one man – who was not and never has been a member of the NGO – must not be used to tarnish the good name of game keeping, which does so much for the countryside and its wildlife.'

Afterwards, the League Against Cruel Sports expressed outrage at the sentence.

Chief executive Joe Duckworth said: 'We are absolutely outraged by this sentence. If killing one bird of prey can equal to a £5000 fine and a six-month spell in prison I cannot comprehend how when you kill 11 birds of prey you only get a 10-week suspended sentence. What sort of message does this send out at a time when we are seeing relentless persecution of birds of prey across the UK?'