A spokesperson for the company Eurotunnel has revealed that the UK and French governments were required by a private arbitration tribunal to pay out nearly 24 million euros for failing to provide adequate security around the entrance to the Channel Tunnel between 1999 and 2002.

While the judgement has long been available on the website of the Permanent Court of Arbitration in the Hague, the size of the award has only now been disclosed in connection with the current migrant crisis in Calais.

The Eurotunnel case is one of only two known instances in which the UK government has faced a claim under the controversial investor-state dispute settlement (ISDS) mechanism, which allows companies to sue governments before private arbitration tribunals for loss of profits.

The other known case involving the UK, which has been shrouded in even greater secrecy, was filed by Indian solicitor Ashok Sancheti under the UK-India bilateral investment treaty, and stems from a rent dispute over premises he had leased from the Corporation of London.

In the Eurotunnel case, the tribunal ruled in favour of the company's claim that the UK and French governments had failed to live up to their responsibilities under the 1986 Treaty of Canterbury, which governs the running of the Channel Tunnel, but dismissed a parallel claim relating to the provision of subsidies by the French government to ferry operator SeaFrance.

It remains unknown whether the UK and France were each required to pay half of the award.

Photo: PCA tribunal members in the Eurotunnel case