An Ombudsman’s investigation is underway following claims that councillors on Pembrokeshire County Council’s Independent group have used local authority computers for electioneering.

This follows publication on a councillor’s website of files and documents which he says give proof that the Independent Plus Political Group (IPG) is actually a ‘well-refined political party’.

Councillor Jacob Williams has made the controversial revelations – which he describes as ‘a scandal’ and has been dubbed ‘Partygate’ – on his website jacobwilliams.com.

The 23-year-old alleges that because he has now ‘proved’ that the IPG is a political party, certain members’ creation and storage of election material on Pembrokeshire County Council’s computer equipment is not only contrary to the authority’s code of conduct but could even be a criminal offence, breaching electoral law.

Councillor Williams, the council’s youngest member, who represents the south Pembrokeshire ward of East Williamston, told the Western Telegraph that he plans to publish several more articles in coming weeks.

He has obtained information and files – including election literature, leaflets, posters, flyers and campaign strategy documents – which show that 13 ‘Independent’ candidates in 2008 and 14 in 2012 were given assistance by the IPG in conducting their election campaigns.

“‘Partygate’ reveals what many have known for years and which the IPG has denied – rather than the coming together of like-minded individuals for the good of Pembrokeshire following election after election, it is, in fact, a political party, and one that is arguably much more successful than any of the registered parties,” Councillor Williams said.

He suggested that the word ‘independent’ ought to be banned from the names of council groups.

“It is supposed to refer to independent councillors like me who are unaffiliated to any group, so when party-political groups use it in their name, that’s clearly unfair and causes confusion.”

Councillor Williams added: “I understand even some serving IPG councillors are shocked by the party-political traits and tactics exposed in this scandal through my website, yet party loyalty is normally something a candidate is proud of.”

The leader of the IPG, Councillor Jamie Adams, who is also leader of the council, was asked by the Western Telegraph if the website claims had caused concern within the group, but replied: “We are a group of likeminded individuals who do not wish to see decisions affecting Pembrokeshire and its citizens unduly influenced by political views emanating from outside the county.”

Pembrokeshire County Council spokesman Len Mullins said: “The matter is being considered by the Public Service Ombudsman for Wales and the council is awaiting his response.

Until then, we are unable to comment further.”