The alleged snooping on Congress vice president Rahul Gandhi was on Monday raised in Rajya Sabha by a vociferous opposition, which demanded a statement by Home Minister Rajnath Singh on the issue.
Raising the issue, Leader of Opposition Ghulam Nabi Azad said religious freedom and political freedom is going down in the country.
"Is the government trying to threaten political parties by such spying? Are they trying to say if we raise our voice, inside or outside parliament, central government will use any tactic to suppress their political rivals," Azad asked.
"Religious freedom is going down, and now political freedom is going down. Home minister should make a statement," he said.
The police last week visited Rahul Gandhi's office and inquired about his physical appearance, his height, colour of eyes and hair, among others.
While the Delhi Police said this was a "routine" exercise, the Congress and other opposition parties termed it "political espionage".
Responding, Leader of House Arun Jaitley said: "You are making a mountain out of what is not even a molehill."