The Sinn Fein spokeswoman on policing, Ms Bairbre de Brun, has accused the RUC of a "conspiracy of silence" over a suspected loyalist paramilitary dossier which contained details of more than 150 nationalists and republicans.
It recently emerged that the force researched the document for two months before informing those named that their details were on the "hit-list".
Ms de Brun said officers had refused to reveal the nature or origin of the threats.
An RUC spokesman said it did not comment on the personal security of individuals.