"This has reference to reports appearing in a section of the media over the past several weeks, mentioning the Prime Minister, and referring to the conduct of some Union Ministers, and alleged misconduct of the Home Minister's son," the PMO said in a statement.
"The reports are plain lies, motivated and constitute a malicious attempt at character assassination and tarnishing the image of the Government," it said.
The statement came in the wake of a media report that Rajnath Singh was unhappy over rumours being spread by "a ministerial colleague" and "party rival" about his son being pulled up by Prime Minister Narendra Modi over some alleged misconduct.
"Those indulging in such rumour-mongering are damaging the interest of the nation. These reports are strongly denied," the PMO said.