Cuba said Wednesday it has launched a probe into how hundreds of thousands of customer mobile phone numbers fell into the hands of a U.S. government programme that used them to secretly set up a mobile-based, Twitter-like social network on the island.

An Associated Press investigation revealed last week that the US Agency for International Development programme (USAID) used the data to build a subscriber base for the platform, dubbed ZunZuneo, with the idea that it could be used to stir unrest.

Cuba considers such USAID programmes to be subversive attempts to topple its Communist-run government. Officials told reporters that state telecom company ETECSA had not provided the data to any international operator or entity, and the information was obtained illegally.

"ETECSA wanted to stress in the statement that its user database has not been released to any operator for privacy issues, nor to an agency or to anyone other than within the company itself," said Daniel Ramos, head of security operations for ETECSA.

He did not give details on the probe's progress or any measures that may be taken.

"We condemn the use of this database, which the company did not agree to. And of course, we do not know how this database could have fallen into the hands of the ZunZuneo platform and others already mentioned," he said.

Ramos said ETECSA detected bulk messages being sent through ZunZuneo starting in September 2009 during a mass concert by Colombian singer Juanes, and again in early 2010.

The company complained to 200 operators that had messaging agreements with ETECSA, and threatened to sever relationships if it continued.

Nonetheless ZunZuneo continued to operate until 2012 and built a base of tens of thousands of users before abruptly disappearing.

And until the recent AP investigation, ETECSA had no idea the messages were anything other than unwanted spam, ETECSA officials said.

Some lawmakers in Washington have expressed support for ZunZuneo since AP's original disclosure.

At a House Foreign Affairs hearing on Wednesday, congresswoman Ileana Ros-Lehtinen, a Republican, said the network was a US-led democracy effort in Cuba which was "transparent" and "one of the most scrutinised programmes in our foreign aid portfolio."

AP TELEVISION

Havana, Cuba - Recent

1. Vehicles driving down street in Havana

2. Street scene in Havana, man looking at smart phone in the foreground

3. Various of people on their phones

AP TELEVISION

Washington, DC - Recent

4. Pan of documents relating to the ZunZuneo network, a text messaging-based social network in Cuba

POOL

Washington, DC - 9 April 2014

5. Wide shot of House Foreign Affairs Committee

6. Mid of USAID (US Agency for International Development) Administrator Rajiv Shah in front of the committee

7. Wide side shot of committee

8. SOUNDBITE: (English) Ileana Ros-Lehtinen, Republican Congresswoman, Florida:

"Contrary to what the media have reported, democracy programmes for Cuba are transparent. They are open. The Cuba Democracy programme with its 20-million-dollar price tag, in fact is one of the most scrutinised programmes in our foreign aid portfolio. The real question here is why does the press and some in our congressional family demonise these programmes?"

AP TELEVISION

Washington, DC - March 2014

9. Exterior shots of the USAID headquarters

10. Flag outside the USAID headquarters

AP TELEVISION

Havana, Cuba - 9 April 2014

11. Wide shot of news conference with managers of Cuba Communications Company

12. SOUNDBITE (Spanish) Daniel Ramos, Head of Security, Cuban State Telecom ETECSA:

"ETECSA (Cuba's state-owned telecom company) wanted to stress in the statement that its user database has not been released to any operator for privacy issues, nor to an agency or to anyone other than within the company itself. We condemn the use of this database, which the company did not agree to. And of course, we do not know how this database could have fallen into the hands of the ZunZuneo platform and others already mentioned."

13. Wide of news conference

14. SOUNDBITE: (Spanish) Daniel Ramos, Head of Security, Cuban State Telecom ETECSA:

"the text messaging service is very cheap, insignificant. We even have agreements with operators where the text messaging service is not charged, so I do not see how that money could have been able to reach ETECSA."

15. Cutaway of cameras

16. SOUNDBITE: (Spanish) Daniel Ramos, Head of Security, Cuban State Telecom ETECSA:

"ETECSA continues to develop its services, but this depends on the level of investments that we make from the economic point of view. And of course, our goal is to prevent anyone from inventing a service for our users. The idea is that the company provides all the possible services to prevent these things from happening."

17. Wide of news conference ending