A former chief executive has been awarded $13.5m (€10m) in libel damages over a naked sleepwalking incident.

Donal Kinsella (67) won the highest libel award in the history of the state in the High Court in Wednesday over a press release issued by his former employer, Kenmare Resources PLC.

The company said they were shocked by the verdict and planned to "immediately and vigorously" appeal to the Supreme Court.

"The amount of €10m is over five times greater than the previous record amount granted in an Irish defamation case. This previous award is currently under appeal as being grossly excessive," a spokesperson added.

"The court has granted a stay on the award, subject to the payment of €500,000, until the hearing of the Supreme Court appeal. Kenmare's legal team strongly advise that the award will be set aside on appeal."

The original press release was issued in July 2007 and announced that the board was to seek the resignation of Mr Kinsella as chairman following “an accident” in which he had sleepwalked into the room of a company secretary, during a business trip to South Africa earlier that year.

According to Mr Kinsella is soon became an “international” laughing stock over the alleged allegations.

An independent inquiry later exonerated the former chairman.

The jury awarded him $12m (€9m) in compensatory damages and a further $1.3 (€1m) for aggravated damages.

Mr Justice Eamon de Valera adjourned the question of the costs until next Wednesday.

The jury found that the press release issued by the company suggested that Mr Kinsella had made inappropriate advances to the Ms Corcoran and that the publication had intended to embarrass him relating to this position in the company.

The court heard that Mr Kinsella had sleepwalked to the door of Ms Corcoran's bedroom on three separate occasions during the night, before the company's MD, Michael Carvill, told him to go back to bed. Mr Kinsella was prone to sleepwalking and had been drinking, he was not wearing any pajamas.

On their return to Ireland, Ms Corcoran had complained about the incident. An independent solicitor was appointed by the company to carry out an investigation. The solicitors report concluded there had been no conscious attempt to enter the secretary's bedroom.