The Garda Síochána Ombudsman Commission has launched an investigation into complaints made in connection with allegations by a former Corrib gas contractor that Shell E&P Ireland supplied a consignment of alcohol to Belmullet Garda Station before Christmas 2007.
The investigation was opened after the commission received statements taken by gardaí.
The commission said that contained in the complaints are allegations that gardaí have been involved in improper practices in accepting alcohol from OSSL on behalf of Shell E&P Ireland Limited.
It is also alleged that gardaí have been neglectful in that they have failed to correctly address or properly investigate these matters since they were reported to them by OSSL in 2011.
Having examined the statements, the commission admitted the complaints for investigation.
Separately, gardaí have conducted a re-examination of the allegations, which was led by Superintendent Thomas Murphy, that alcohol from Shell E&P Ireland Limited was distributed to members of the force.
Allegations had previously been investigated by gardaí and no evidence of this happening was found.
In a statement, Shell E&P Ireland Limited said it welcomed the ombudsman investigation into OSSL's allegations.
It said that in recent weeks the company provided information to Supt Murphy's examination and will also co-operate fully with the ombudsman's forthcoming investigation.
The company said "these allegations have dragged on for a long period" and trusted that the ombudsman's involvement will bring the matter to an end.
OSSL was a contractor employed by the Corrib gas project from 2005 to 2010.
In a statement,