According to an investigation done by The Indian Express, on September 7 last year, the Finance Minister wrote to Prime Minister Manmohan Singh asking him to order a "secret inquiry" into what he called a "serious breach of security" in his office - the presence of "planted adhesives" in 16 key locations that suggested a possible surveillance attempt.
These locations included the office of the Finance Minister himself, the office of his adviser, the office of his Private Secretary, and two conference rooms used by the Finance Minister. In his letter, Mukherjee had mentioned that no "live microphone" or recording devices were found.
"In respect of news item regarding bugging in my office, the IB investigated into it and found there is nothing in it," said Mukherjee.
The Indian Express reports that Mr Mukherjee's letter came three days after an unprecedented "electronic sweep" of the Ministry's VVIP chambers was conducted by a team of private investigators brought in by the Central Board of Direct Taxes (CBDT).
After an investigation, the Intelligence Bureau (IB) reported that the adhesives were sort of "chewing gum" but in contrast, the Central Board of Direct Taxes (CBDT) said the tiny devices that were pasted, and then pulled out.