A police officer was discriminated against because he was not a Mason, an employment tribunal has ruled.
The tribunal ruled Masonic Order membership was a religious belief
Royal Ulster Constabulary Reserve Constable Joseph Gibson was moved from the motor transport depot in 1999 during staff cutbacks.
Another reservist who was retained was not as well trained as Mr Gibson but was a member of the Masonic Order.
The Fair Employment Tribunal held Mr Gibson was unlawfully discriminated against on grounds of religious belief.
It also held that the constable retained was a member of the Masonic Order, as was at least one other person involved in the selection process.
In a ruling the tribunal declared: "The respondents did not provide a neutral working environment.
"As a result, those officers who did not belong to the Masonic Order felt uncomfortable and excluded because of the actions of those who did."
The tribunal will reconvene to decide upon the appropriate remedy.
The tribunal said membership of the Masonic Order is a religious belief for the purposes of the Fair Employment and Treatment (Northern Ireland) Order 1998.
The tribunal concluded "the decision to transfer the claimant from the RUC Motor Transport Depot was unlawful discrimination on grounds of religious belief".
Mr Gibson brought the case before the tribunal, with the assistance of the Equality Commission.
Eileen Lavery, head of legal services in the Equality Commission, said people could not be discriminated against because they were not Masons.
"The ruling of the tribunal is clear - that in the workplace it is unlawful to discriminate against someone because they are not a Mason," she said.
"It does not say that membership of the Masonic Order is incompatible with any particular employment, but rather that taking decisions in the workplace which favour one person to the detriment of another, based on Masonic membership, is unlawful."
Mr Gibson, now 67, originally from Belfast, took the case against the RUC - which has since become the Police Service of Northern Ireland - and the now defunct NI Police Authority after being among the officers selected for transfer.
The staff reduction followed a decision to switch prisoner escort duties to the Prison Service.
A spokeswoman for the Police Service of Northern Ireland said the force was studying the judgement closely.