A British agent who infiltrated the Provisional IRA is threatening legal action against the Chief Constable of the Police Service of Northern Ireland if he refuses to give him information about dissident republican threats against his life.

Kevin Fulton from Newry, who is living at a secret location in Britain, is demanding to know why Hugh Orde and the PSNI haven't made contact with him after the Real IRA named him as a target.

The threat against Fulton was made by a Real IRA Army Council representative in a Sunday Tribune interview last month. The Real IRA admitted killing British agent and Sinn Féin former chief administrator at Stormont Denis Donaldson, and threatened other informers including Fulton, Martin McGartland, Raymond Gilmour, and Freddie Scapaticci.

In a letter to Orde, shown to the Sunday Tribune, Fulton wrote: "I believe my human rights have been violated by you and your police force by not informing me of these threats from a terrorist organisation.

"If these threats were made against any other person in any other part of the civilised world, they would be told. In this case, you have no excuse in not informing me. Is this a deliberate action on you and your police force's part?

"Do you have the right to decide if my life is worth more than the Deputy First Minister's?" The North's Deputy First Minister, Sinn Féin's Martin McGuinness, was recently informed by the PSNI that his life was under threat from dissidents.

Fulton told Orde: "I demand that you and your police force inform me of any threats against my life and let me have a fighting chance to defend myself. Am I and others to depend on the media for this information?

"I demand to know if and when any threat is made, even if you or your officers do not regard it to be a serious one. We've seen in the past where your officers got it wrong."

Fulton said if he didn't receive this information he would "have no other conclusion to come to other than police and others within the security services wish to see me dead or caused serious harm in an effort to silence me and cover up the actions of myself and my handlers – officers from the police, army and security services – carried out in Northern Ireland from 1979-2001."

Fulton claimed that three days before the Omagh bomb, he told his handlers that a Real IRA man he knew had smelt of fertiliser and that the group were preparing to "move something North".

Fulton's disclosure was a huge embarrassment to the security services who have been criticised for their failures over Omagh.