Uttar Pradesh Chief Minister Mulayam Singh Yadav's move to grant tax-free status to the crime caper "Bunty Aur Babli" has enraged the Congress, which accuses him of playing favourite with Amitabh Bachchan movies.

And "Bunty Aur Babli", which became tax-free from Wednesday, stars not only Bachchan senior in a cameo but also son Abhishek Bachchan in the lead along with Rani Mukherjee.

"This special concession to all Bachchan films needs to be probed," said state Congress spokesperson Akhilesh Singh.

Congress workers point out that even a patriotic film like "Bose - The Forgotten Hero", which focuses on the life of Netaji Subhas Chandra Bose, did not attract tax-free status.

A look at the state's entertainment tax records reveals that of the 30 films declared tax-free by the Mulayam Singh Yadav government, as many as 16 feature either Amitabh or Abhishek in the lead.

The Congress alleges that special favours were being extended to the Bachchan family because Amitabh heads a film subcommittee of the Uttar Pradesh Development Council, chaired by Samajwadi Party leader and close friend Amar Singh.

"One important criterion for tax exemption is that the particular film should convey a healthy and positive message to society. But, in this case, 'Bunty aur Babli' has a totally negative theme - use the wrong means to get rich and you will get away with murder," Singh said in a statement.

The state's entertainment tax commissioner Mohan Swaroop has denied the allegations. "There are certain norms laid down for exempting films from entertainment tax and whatever has been done is in accordance with those norms."

According to Swaroop: "Shooting more than 70 percent of a film within the state is one of the criterion for seeking tax exemption; and 'Bunty Aur Babli' fulfils that criterion. A lot of Bhojpuri films shot in Uttar Pradesh have also been exempted from entertainment tax."