A hidden microphone has been found in the Ecuadorian embassy in London where WikiLeaks founder Julian Assange is sheltering from extradition to Sweden.
The bug was found in the office of the ambassador Ana Alban during a routine search ahead of foreign minister Ricardo Patino's visit in mid-June, AFP reported.
Patino said the origin of the bug would be revealed but did not elaborate.
"We have found a hidden microphone in the London embassy," said Patino. "I did not bring this up before because I didn't want my visit to London to hold talks on Julian Assange to be confused with accusations over this surveillance device found in the ambassador's office."
It is unclear whether the bug was connected to the drama surrounding fugitive surveillance whistleblower Edward Snowden, who has also applied for asylum in Ecuador.
Patino expressed his fears that the Ecuadorian government was being "infiltrated from all sides".
"This is a testament to the loss of ethics at an international level in the relations that we have with other governments," he said.
Sieging/bugging of Ecuador's London embassy and the blockading of Morales jet shows that imperial arrogance is the gift that keeps on giving
— WikiLeaks (@wikileaks) July 3, 2013
Assange has been holing up in the Ecuadoran embassy in London for a year. He faces questioning over sexual assault allegations in Sweden.
Patino held talks with his British counterpart William Hague to push for the safe conduct of Assange to Ecuador, where he has been granted asylum but no agreement was made.
Ecuador was assessing the asylum request from Snowden who is believed to be still stuck in the transit zone of Moscow's Sheremetyevo airport.