The US authorities' clampdown on online gambling businesses will not hit Dublin-listed bookmaker Paddy Power or other Irish-based gaming operations.

The sector was thrown into turmoil this week when the US Federal Bureau of Investigation charged leading figures in the industry.

David Carruthers, chief executive of BetonSports, which has a considerable US business, was arrested as part of the crackdown.

Many Irish and European-based bookmaking and gambling-related businesses have substantial online operations, but block access to US-based customers.

A Paddy Power spokesman said yesterday that it used a number of systems to block access to its site from the US.