Mumbai, Feb 19 (IANS): Assailing the Maharashtra government for another month-long extension of parole for Sanjay Dutt, the BJP Wednesday demanded to know why the Bollywood actor was being treated as a "state guest prisoner".

In a letter to Chief Minister Prithviraj Chavan, senior state BJP leader Kirit Somaiya said not a single person or convict has been accorded such extraordinary special treatment or parole in the past 50 years.

"What if other such prisoners or those involved in terror acts ask for continuous parole?" Somaiya demanded.

His letter came hours after BJP's Leader of Opposition in the Council Vinod Tawde Tuesday night criticised the government for the third -- and latest -- parole of one month granted to Sanjay Dutt till March 21, on grounds of his wife Maanyata's illness.

"There are many convicts serving terms who had demanded parole but it had been continuously rejected. Dutt may be technically correct, but the government must understand who they are favouring and the kind of message being conveyed to society," Tawde said.

He said the only possible reason for the state government to concede all parole applications made by Dutt was that his sister Priya Dutt is a Congress MP and close to the central party leadership.

Ten days ago, Dutt applied for a third extension of parole, citing his wife's Maanyata's medical grounds and the plea was approved Tuesday.

Dutt is out on parole from Pune's Yerawada Central Jail since Dec 21, 2013.

Prior to this, he was released on a fortnight-long furlough, which was extended by another fortnight in October 2013.

An accused in the March 1993 Mumbai serial blasts case, Dutt is serving the remaining 42 months of his five-year prison sentence.

His wife Maanyata was diagnosed as suffering from multiple heart and liver ailments a few months ago and underwent a surgery in a Mumbai hospital last month.