But the word spread rapidly among journalists in Paris, prompting Arret Sur Images to start chasing the report, he said.

CNN: Sarkozy, Obama bemoan Netanyahu over open mic

Arret Sur Images ("Freeze Frame") said journalists had listened in on the conversation but had agreed not to report it.

CNN: Sarkozy, Obama bemoan Netanyahu over open mic

Dan Israel, the Arret Sur Images writer who broke the story, told CNN that about three minutes of the leaders' private conversation could be heard.

CNN: Sarkozy, Obama bemoan Netanyahu over open mic

Its contents were first reported by the French website Arret Sur Images, which said reporters heard Sarkozy's comments in French and Obama's reply through a translator.

CNN: Sarkozy, Obama bemoan Netanyahu over open mic

"We didn't record it, and to use it would force us to admit that we had cheated, " Arret Sur Images quoted one of the reporters who heard the conversation, whom it did not name.

CNN: Sarkozy, Obama bemoan Netanyahu over open mic