By Alexandra Valencia and Estelle Shirbon
QUITO/LONDON (Reuters) - Ecuador said on Wednesday it would seek the help of the British government to determine who put a hidden microphone in the South American nation's London embassy, where WikiLeaks founder Julian Assange is holed up.
Foreign Minister Ricardo Patino Patino said a microphone was found inside the office of the ambassador to the United Kingdom, Ana Alban, while he visited the embassy to meet with WikiLeaks founder Julian Assange on June 16.
Assange, who was granted asylum by Ecuador last year, lives and works in a different room within the embassy.
"After this discovery, the government of Ecuador will request the collaboration of the British government in investigating this issue to discover who is implicated in this espionage operation," Patino told a news conference in Quito.
Earlier in the day, the Foreign Office in London declined immediate comment on the allegation and Prime Minister David Cameron's spokesman said he did not comment on security issues.
Patino added that Ecuadorean authorities "have reason to believe that the bugging was being carried out by the company, the Surveillance Group Limited, ... one of the biggest private investigation and undercover surveillance companies in the United Kingdom," he said.
The Surveillance Group did not immediately respond to an email seeking comment.
Ecuador's protection of Assange has strained relations with Britain. The Foreign Office said after a meeting between British Foreign Secretary William Hague and Patino on June 17 that no substantive progress had been made to break the legal and diplomatic deadlock.
Assange has been living inside the embassy for more than a year to avoid extradition to Sweden to face allegations by two women of sexual assault and rape, which he denies. He cannot leave the embassy because Britain will not give him safe passage.
He fears that if sent to Sweden he could be extradited from there to the United States to face potential charges over the release of thousands of confidential U.S. documents on WikiLeaks.
WikiLeaks used its Twitter account to condemn the hidden microphone.
"Sieging/bugging of Ecuador's London embassy ... shows that imperial arrogance is the gift that keeps on giving," the anti-secrecy group said.
(Writing by Brian Ellsworth, Editing by Jon Boyle and Sandra Maler)