The Irish Council for Civil Liberties is taking legal action against the Data Protection Commission accusing it of failing to properly investigate Google.

The ICCL's complaint relates to Google's 'Real-Time Bidding' online advertising system, the process of auctioning advertising space as people browse online.

The ICCL says the system involves broadcasting private information about internet users in a split second and describes it as "the largest data breach ever".

The Irish Council for Civil Liberties complained to the Data Protection Commission in September 2018 and the Commission opened an investigation into the matter in May 2019.

The ICCL is accusing of the DPC of failing to act and allowing the alleged data breach to continue.

The ICCL also claims that the investigation launched by the DPC fails to address the critical issue of data security.

The High Court has granted leave for the ICCL to take legal action against the DPC for inaction.

"We are concerned that the rights of individuals across the EU are in jeopardy because the DPC has failed to investigate Google's RTB system over three and half years," said Liam Herrick, Executive Director of ICCL.

The plaintiff in the case is Dr Johnny Ryan, a Senior Fellow at ICCL.

"The DPC was created to protect us against the illegal collection and use of intimate data about us but it has failed to act in this landmark case," Dr Ryan said.

Graham Doyle, deputy commissioner with the Data Protection Commission said its investigation into Google's 'Real-Time Bidding' advertising system is ongoing.

Google says that authorised buyers using its systems are subject to stringent policies and standards.

"We will engage fully with the DPC’s investigation and welcome the opportunity for further clarification of Europe’s data protection rules for real-time bidding," a Google spokesperson said.