The US created a text-message social network designed to foment unrest in Cuba, according to an investigation by the Associated Press news agency.

In a daily news conference at the White House, Obama administration spokesman Jay Carney confirmed US involvement in the project, saying it was neither "covert nor an intelligence programme".

"This was a programme that has been invested in and debated by in Congress," Mr Carney said.

"The GAO [Government Accountability Office] has reviewed this programme in detail less than two years ago and found it was conducted in accordance with US law and under appropriate oversight controls."