FIVE-year-old ballot papers and election material containing people’s personal details have been discovered in a disused council building.

Powys council has now apologised for failing to destroy the material which included statements signed by people who returned postal votes to the council and ballot papers cast in the 2011 referendum on granting the Welsh Assembly full law-making powers.

The authority said the discovery has also been reported to the Information Commissioner and the papers had now been destroyed.

The hoard was discovered by Martyn Morris and his 28-year-old son Ashley who describe themselves as "urban explorers". Martyn Morris said they found the papers after they entered the former Powys Archives building which is in the grounds of County Hall in Llandrindod Wells.

The council said the building had been "broken into". Dyfed-Powys Police said following enquiries no offences were identified.

Martyn, 47, said he and his son discovered the papers on Saturday, June 4 and posted photographs of what they had found on Facebook.

Last week Dyfed-Powys Police officers visited Ashley’s work place at Penybont and asked him to remove the photographs.

Martyn said they discovered a mine of personal information: "The building was all boarded up but we went around the back and there was a window with no glass in it and we climbed into the building.

"There was not much natural light in there and we came across a room that was half full of brown paper sacks and on them was a label saying they were postal votes from the 2011 Welsh Assembly Referendum."

Photographs seen by The Brecon & Radnor Express show the brown paper sacks clearly marked "County of Powys Packet B postal votes" with "B + R" handwritten on the label that has been dated 23/2/11 and signed by a counting officer. The referendum was held on March 2 that year.

Photographs of statements returned with postal votes, signed and dated, with the voter’s date of birth, have also been shown to us.

"It is a derelict building full of people’s personal information, five years down the line," said Martin who also said they found a ballot box in the room.

"If the wrong people had got into that building they would have the personal information for everyone in Powys.

"What concerns me is the amount of personal information left in there."

He added: "The police turned up at Ashley’s work and asked for the photos to be removed from Facebook. The police said they didn’t care how we got it they just wanted the photos taken down."

Powys council said the papers were stored in sealed bags in a secure building near County Hall, were being retained for the statutory 12 month period required after an election but were not destroyed due to an oversight.

A spokesman said in a statement: "The issue was discovered when the building was broken-into and a photograph and comments were posted on social media. The break-in was immediately reported to police and the material which included processed ballot papers and postal votes dating back to 2011 were destroyed immediately as confidential waste."

The council’s cabinet member for legal services Councillor Wynne Jones said: "The material which had been used in past elections and had been properly accounted for was being stored for the required 12 months. It should have been destroyed at the end of the storage period but was not due to an oversight and for that we apologise.

"The matter was reported to police and immediate action taken to destroy the material. The building has been secured and the issue reported to the Information Commissioner."

The Electoral Commission said election material must be disposed of confidentially but it is a matter for individual councils how they do that.

A police spokeswoman said: "Dyfed-Powys Police received a report on June 7 that a man had entered the old Powys Archives building in Llandrindod Wells without authority to do so. No damage was caused during entry. "Subsequently, the man posted photos of himself inside the property on Facebook.

"Officers traced the man in question, gave him words of advice in relation to his actions, and requested that he removed the photos from Facebook – which he agreed to do. Following enquiries, no offences identified."