The Welsh Government is reviewing its procedures after it mistakenly released the names of farms involved in the badger cull.

It blamed an “administrative error” for the mistake which saw an “element of personal data” published in response to a freedom of information request.

Anti-cull campaigners Stop the Welsh Cull published on Facebook what it claimed were the names of three farms where the Welsh Government culled five badgers last year.

The group claimed it had been able to identify the names and locations of the three Welsh farms involved in the targeted cull.

In the posting, the group said: “We can now reveal the three farms where the Welsh Government killed five badgers in 2017 at a cost of over £380,000 with badgers testing positive using a rubbish test but confirmed negative for bovine TB at post mortem.

“Documents released as a result of a Freedom of Information request show the detailed work plan drawn up by the Animal and Plant Health Agency for each of these farms, including their names.

“Operations may have already started at these farms this year. We are asking people to monitor activity at these farms, looking for unusual activity that could indicate killing has restarted and let us know.

“Also report lapses in biosecurity measures the farms involved are obliged to carry out.”

The group defended posting the information and said: “Just so we’re clear: Not irresponsible: Sharing info released by Government.”

They said the Welsh Government was “irresponsible” for “wasting public money” and “pursuing policies experts say spread TB”.

A Welsh Government spokeswoman said: “Due to an administrative error, a document sent in response to a freedom of information request was released without removing an element of personal data.

“We are urgently reviewing our procedures in light of this error.”

The localised culling of badgers in Wales last year is part of Welsh Government efforts to tackle TB in wildlife.

NFU Cymru president John Davies said: “We’re extremely concerned and disappointed that this information has come into the public domain.

“The Welsh Government must now carry out a full investigation into how this breach of data has occurred.

“There is no doubt that this breach will impact on farmers’ confidence in Welsh Government’s approach to tackling this horrendous disease.

“Our primary concern now is for the wellbeing of those farmers affected by this breach.”

A Farmers’ Union of Wales spokeswoman said: “This is naturally a big safety worry for the farming families involved.

“Bovine TB remains a big problem and the culling of badgers to combat the wildlife reservoir of the disease is a contentious one.

“We therefore hope that Welsh Government will do all they can to protect those families and get to the bottom of how such confidential information was released in the first place.”