Sinn Féin last night (Friday) cast doubt over the process whereby police officers must declare their membership of so-called secret societies.
It came after the PSNI confirmed that 91% of its personnel recorded that they were not members of any notifiable organisations.
Under the Registration of Notifiable Memberships scheme, officers must declare their associations with groups such as the Orange Order and Free Masons.
It extends to the loyalist Apprentice Boys of Derry and Royal Black Institution and nationalist Ancient Order of Hibernians, as well as any other groups which may be perceived to be in conflict with an officer's job.
New figures have revealed that 94% of officers have registered under the scheme with the majority declaring they were not members of any notifiable organisations.
It was further shown that 5.3% of police officers were members of the Freemasons; 1.9% of the Loyal Orange Institution; 1.1% of the Royal Black Institution; and 0.33% of the Apprentice Boys of Derry.
Knights of St Columbanus and the Ancient Order of Hibernians membership was 0.28%, while 0.06% of officers were members of the Independent Orange Order.
Sinn Féin MP Michelle Gildernew said: "People will also be concerned to know how exactly this information can be validated.
"Many people believe that membership of secret societies or sectarian and anti-Catholic organisations like the Orange Order is no place for anyone involved in an impartial policing service."
Police said efforts were being made to ensure those officers who had not registered did so.
A police spokeswoman said an officer who refused to complete a registration form would be in breach of an order and "under the Code of Ethics they would be subject of disciplinary proceedings."
Assistant Chief Constable Judith Gillespie said the scheme was a "positive step, promoting openness and transparency and enabling the Police Service to address the diverse perceptions reflected in the community.
"In responding to this statutory requirement, it is hoped that the Police Service will be able to strengthen community confidence in the impartiality of police officers."
Alex Attwood, SDLP Policing Board member, said it was "encouraging" that 94% of officers had registered an interest.
Mr Attwood said the 5.3% officer membership of the Freemasons, though not a surprising figure, was an issue which needed to be "further looked at".
"The SDLP accept at face value the numbers of people who have declared to be in marching orders," he said.
"The low numbers should give people confidence that there is not any interference in police by marching orders."
Ulster Unionist Fred Cobain said: "If people are members of organisations, it's a matter for themselves provided they do a professional job.
"I don't think any of the notifiable organisations would stop anyone from doing a professional policing job," he said.