The Justice Minister is being called on to begin an independent inquiry into the GSOC officer who resigned over claims about Gerry Hutch.
The officer is alleged to have attended a house party, which '''the Monk'' also attended, after he was acquitted of the Regency Hotel murder.
Labour's Justice spokesperson Aodhán Ó Ríordáin says GSOC shouldn't be investigating.
''We can't have GSOC investigating themselves. We need an outside agency. I suggested either a retired judge or a senior counsel to look over the facts, to look over this incident and to see what learnings should come from this because certainly there is a huge amount of disquiet over it.''
The claims emerged over the weekend with a spokesperson for the Garda Siochana Ombudsman Commission (Gsoc) saying an investigation is ongoing.
A spokesperson for the Minister for Justice said they were aware of the incident involving an issue with a Gsoc member but added it would not be appropriate to comment on individual cases.