The home ministry Monday denied the reported bugging at union Minister Nitin Gadkari's residence, and ruled out any probe.
Asked about the bugging, union Home Minister Rajnath Singh said: "There is no contradiction, Gadkari has denied it himself."
Minister of State for Home Affairs Kiren Rijiju too refused to comment.
"The minister himself has said the reports are speculative... How can we comment on it?" Rijiju said when he was asked if the home ministry would probe the bugging reports.
"There is nothing concrete in it," the minister said.
Media reports Sunday said a bugging device was found at Gadkari's Delhi residence.
This was, however, denied by Gadkari and those close to him.
"Reports in a section of the media about listening devices having been found at my New Delhi residence are highly speculative," Gadkari tweeted.
The Congress demanded a probe into the allegations, with former prime minister Manmohan Singh saying it is not a "good omen".
"If ministers' houses are bugged, then it is not a good omen. It should be investigated. How can it happen? It should be explained by the government in the house," the former prime minister told reporters at an Iftar get-together hosted by Congress president Sonia Gandhi.
BJP spokesperson Mukhtar Abbas Naqvi asked why Manmohan Singh was quiet when bugging was reported in then finance minister Pranab Mukherjee's office.
"Why was Manmohan Singh quiet when there were reports of bugging of his ministers," Naqvi asked.