Fine Gael TD and MEP Mr Gay Mitchell has linked republicans to the disappearance of letters he sent to his constituents.
Mr Mitchell yesterday demanded a full inquiry by the Houses of the Oireachtas and An Post into the disappearance of three letters he wrote to constituents last February.
He claims that three letters sent in Oireachtas envelopes on February 12th, 17th and 20th to three different parts of one parish in his Dublin South Central constituency never arrived.
"I don't know who is involved, but we have had evidence that republicans put members of the Oireachtas under surveillance," said Mr Mitchell, who has written in April and June to the Ceann Comhairle, Dr Rory O'Hanlon.
"Given that there is evidence that republicans had put TDs under surveillance there has to be a lot of suspicions. There are constitutional issues here. Citizens have a right to deal privately with their TDs," he said.
The Oireachtas authorities said last night the Superintendent of the Houses of the Oireachtas, Mr Paul Conway, had carried out an inquiry on foot of a complaint by Mr Mitchell and he was satisfied the letters had left Leinster House.
"I am told they found nothing untoward. They were in contact with An Post," a spokesman for the Houses of the Oireachtas said, adding that the issue was not raised at the Committee on Procedures and Privileges.
A spokesman for An Post said last night: "We are perfectly ready to carry out an investigation on being furnished with the details of the case."
However, Mr Mitchell said he had sought an inquiry by the Committee on Procedures and Privileges from the Ceann Comhairle, but so far had not received a response.
"In 20 years I have never had anything like this happen before. We are talking about letters to three different people in three different parts of a parish over a number of days," said Mr Mitchell.
The Central Criminal Court last week convicted two Sinn Féin members, Niall Binéad and Kenneth Donohoe, of IRA membership, following evidence that Oireachtas members had been put under surveillance.
In a search of Mr Binéad's home, detectives found a list written on cigarette paper that included details about the movements of two politicians - the Fianna Fáil TD, Dr Jim McDaid, and the ex-Fine Gael TD, Mr Brendan McGahon.
The list named other politicians, including former PD leader and minister for justice, Mr Des O'Malley, and former justice minister Mr John O'Donoghue.
Binéad and Donohoe, who were arrested in 2002 after gardaí noticed the occupants of three cars behaving suspiciously in Bray, Co Wicklow, are to be sentenced shortly.
The Minister for Justice, Mr McDowell, said: "For the last two years I have been saying that the IRA and criminality are an ongoing phenomenon. I have been asked to put up or shut up. I think now it is about time for other people to put up information about what was happening on that day."
Sinn Féin Dublin South Central TD, Mr Aengus Ó Snodaigh, who is a close associate of Binéad, has again criticised his conviction by the Central Criminal Court. "I don't believe the conviction is just and would stand up in any other court."
