A UK-based surveillance group has denied claims that it was behind the bugging of the Ecuadorian embassy in London, where WikiLeaks founder Julian Assange has been living for the past year.
Ecuador's foreign minister Ricardo Patino told a news conference in Quito that the bug was found last month when technicians reviewed the embassy's wiring.
He said that the purpose of the hidden microphone was to listen to the conversations of Ecuador's UK ambassador Ana Alban in her office.
"We have reason to believe that the bugging was carried out by The Surveillance Group Limited, one of the largest private investigation and covert surveillance companies in the United Kingdom," he said.
The foreign minister said Ecuador was going to ask the British government to help investigate the alleged bugging, adding that the system worked with a sim card and could be activated by a call from any mobile or fixed-line phone.
A statement by the Worcester-based Surveillance Group's chief executive, Timothy Young, said: "We have this morning heard an accusation the source of which is apparently Ricardo Patino, the Ecuadorian Foreign Minister suggesting that we have bugged the Ecuadorian Embassy.
"This is completely untrue. The Surveillance Group do not and have never been engaged in any activities of this nature. We have not been contacted by any member of the Ecuadorian Government and our first notification about this incident was via the press this morning. This is a wholly untrue assertion."
Mr Assange has been granted political asylum by Ecuador after suddenly arriving at the embassy as part of his attempt to avoid extradition to Sweden, where he is wanted for questioning about sex assault allegations against two women - allegations he denies.
He fears that if he travels to Sweden he will be sent to the US and face charges over the publication of sensitive information by WikiLeaks.