Staff at a free-range farm near Stevenage are concerned people could become ill if they eat turkeys – recently treated with a worming agent – that have been stolen by bungling burglars from their fields.

The thieves probably thought they had bagged a Christmas bargain when they climbed over a six-foot fence at Church Farm in Ardeley and stole eight of the farm’s 19 Norfolk black turkeys – which can fetch up to £120 each – in two separate burglaries on Friday and Saturday.

But farm manager Tom Large says people should avoid buying any birds if they are not sure where they came from, as they could be poisoned by the worming agents.

He said: “We need to warn anyone who buys a turkey from an unknown source to be careful as it could poison them.

“I don’t think the worming agent could kill anyone, but it could make them ill.

“I’d also be very concerned about the way the turkeys have been butchered as the people who did this probably won’t have clean facilities or any knowledge of butchery.”

He added: “I just think it’s disgusting what they’ve done. It’s a small family-run community business – we work with school groups and we’re trying to do as much as we can to involve the community.

“It’s disappointing and upsetting. We’ve worked hard all year to look after these birds.

“We were keeping these turkeys in the field to breed so that they could be part of our community farm and we could raise chicks and let the school children see them and name them. But none of that’s going to happen now.”

Tom said you could still see footprints in the field the day after the thefts where the culprits had approached a fence across a field. There were also imprints in the mesh fence where the thieves had tried to scale it.

He says the farm is protected by CCTV and alarms, but believes the thieves may have visited during the day to plan how they were gong to carry out the robbery.

The farm is owned by Tim Waygood, who inherited it from his parents.

It has cattle, sheep, pigs and poultry, a farm shop, cafe and pub. It also offers camping, wood cabins for hire and egg collecting.

You can find out more at www.churchfarmardeley.co.uk.

Anyone with information about the thefts should call Herts police on 101.