The Gardaí Síochána Ombudsman Commission has found that there is no evidence to suggest that Shell E&P Ireland supplied alcohol to Garda stations in Co Mayo.
A GSOC investigation has also concluded that there was no Garda misconduct in relation to allegations made in this regard.
In a two-page report published this evening, the Ombusdman Commission says the allegations had the potential to undermine confidence in An Garda Síochána.
GSOC carried out the inquiry after receiving two complaints last October from a former contractor on the Corrib Gas project. OSSL was employed by Shell from 2005 to 2010.
The complaints alleged that they had supplied alcohol - on behalf of Shell - to Garda stations in Co Mayo between 2005 and 2007.
They claimed they had reported this to Gardaí in 2011 and that the matter had not been properly investigated.
GSOC says its investigation included numerous interviews with the OSSL complainants, during which they were told of the need to retrieve documents which would provide evidence to substantiate their claims.
The report says that after a meeting about this, the complaints indicated that they would not be co-operating further with the investigation.
The Ombudsman Commission then tried to establish if there was other evidence to support the allegations.
A senior representative of Shell E&P Ireland was interviewed and the company supplied internal documentation to GSOC about its own investigation into the allegations.
A number of gardaí were also interviewed and correspondence with complainants and the force was also reviewed.
At the conclusion of this process, no evidence of the purchase or delivery of alcohol to Garda stations was found.
Shell has welcomed the GSOC findings. In a statement tonight, the company's Managing Director, Michael Crothers said the allegations had been treated with the utmost gravity.
He said they were contrary to Shell's business principles and had a negative impact on staff and locals in north Mayo.