Vidya Balan won't do 'M S Subbulakshmi' biopic?

It’s the season for biopics now in Bollywood, Paan Singh Tomar, Dirty Picture, latest being Bhaag Milkha Bhaag, all have been liked by the audiences as well as critics. There are more to come soon that include biopic on famous boxer Mary Kom, mathematician Srinivasa Ramanujam, but, filmmakers are not stopping here.
Next is a biopic on famous Carnatic singer M S Subbulakshmi.Reportedly, Vidya Balan was to act in the film, but she has never officially declared her association with the movie. Maybe the legal obstacles coming in the way are among the reasons behind it.
Interestingly, the last biopic done by Vidya was on a sex symbol and the next is on a Bharat Ratna winner. This could be another reason, why Vidya is giving the project a rethink.