Sinn Féin minister Mr Martin McGuinness says he and his wife have been warned they are being targeted by loyalist paramilitaries.
Mr McGuinness said they had been informed by the RUC to review their personal security after threats by loyalists.
Several other leading Sinn Féin members have also been warned in recent days, it was claimed. They are reported to include Assembly member Ms Michelle Gildernew, national chairman Mr Mitchel McLaughlin and Derry City Mayor Mr Cathal Crumley.
The RUC warned several republicans in Northern Ireland following the discovery of names of leading republicans on computer files linked to a loyalist paramilitary group.
A statement on behalf of Mr McGuinness expressed concern about the threats. It said: "This is a very serious development. It is a particular worry that my wife's details have appeared. I would urge all republicans to be on their guard following this very serious development."
An RUC spokesman would not comment on Mr McGuinness's claim, saying it was not policy to discuss specific cases.
He said: "Where it is believed a person's life to be in danger, we inform that person to enable him or her to take steps to guarantee their personal safety."
PA