A challenge to the seizure of certain emails of a senior executive of cement giant CRH during a search of a subsidiary's premises as part of an investigation into alleged anti-competitive practices has opened at the High Court.

The Competition and Consumer Protection Commission was not entitled to "essentially run riot" in the premises of Irish Cement Ltd (ICL) at Platin, Co Meath, and just seize all material, regardless of relevance to the purpose of its search, Paul Sreenan SC said.

ICL objected, as "a matter of principle", to the seizure and retention of emails of Seamus Lynch relating to his role within CRH but had no objection to the commission examining emails related to his previous role within ICL, counsel said.

Mr Lynch left ICL in June 2011 to join CRH and, when the search was carried out in May 2014, was managing director of CRH Europe (Ireland and Spain), counsel said. The District Court warrant authorising the search only entitled the commission to seize documents related to ICL, he said.

Mr Sreenan was opening the challenge by ICL, Mr Lynch and CRH arising from the unannounced search at the ICL plant at Platin, near Drogheda.

ICL, a subsidiary of CRH plc, is involved in production and supply of bagged cement products and the search was conducted as part of an investigation into alleged anti-competitive practices in that sector.

When seeking the search warrant, the commission told the District Court it had formed the opinion ICL, from January 2011 to the date the warrant was sought, may have engaged in abuse of a dominant position in relation to bagged cement.

In their challenge, the plaintiffs claim the officers were not entitled to seize and retain any electronic files within a crh.com email account of Mr Lynch which were unrelated to the business and activity of ICL.

The commission denies all claims. It previously agreed not to use the material pending the outcome of the case.