PRISON bosses are investigating claims of a sexual relationship between an inmate and a woman staff member at Portland's Verne jail.

Prisoner David Armstrong has been moved to another Dorset institution while his allegations are being probed.

In a letter sent to the Dorset Echo, Mr Armstrong, who is now a prisoner at Guys Marsh Prison, near Shaftesbury, claims he had an affair with a female staff member while he was an inmate at The Verne.

He also states he has been moved to Guys Marsh from The Verne as a punishment for having the relationship.

The Dorset Echo contacted Mike Cook, governor of The Verne, after we received the letter.

Mr Cook confirmed an investigation has been launched following information he received about what he terms "an alleged improper relationship" between a prisoner and a staff member.

He added Mr Armstrong's transfer to Guys Marsh is not a punishment but part of procedure during investigations.

In the letter, Mr Armstrong said: "I was in HMP The Verne on Portland when I was moved out for having a sexual relationship with a member of staff.

"She started to come on to me first and when things started to get hot she went and told security so we are under investigation."

Mr Armstrong said he has been transferred to Guys Marsh where he is a category C and D prisoner.

He claims that not only was he moved from The Verne as a punishment for getting involved in the relationship but he is also getting very little exercise at Guys Marsh. He added: "I am in Guys Marsh as a category C and D and I'm mostly banged up. Exercise is nil."

Mr Armstrong added: "I am being punished for an affair that was not just my fault as it takes two to tango."

Mr Cook said: "Investigations are a very common occurrence in prisons involving both prisoners and staff.

"Every allegation and accusation made towards prisoners or staff are investigated.

"During investigations sometimes prisoners are moved and sometimes member of staff are moved to different prisons.

"The prisoner has been moved to Guys Marsh while this investigation into an alleged improper relationship is conducted."

He added: "The female member of staff has not been suspended. The investigation could take a number of weeks before any conclusion is reached."