A defamation case has been filed against Bollywood actor Tanushree Dutta for her comments about Maharashtra Navnirman Sena (MNS) chief Raj Thackeray, police said on Thursday.

The case was filed by the Kaij police in Maharashtra's Beed district on Wednesday evening after MNS district unit president Sumant Dhas lodged a complaint, alleging that Dutta had defamed his party chief, a police officer said.

"We have registered a non-cognisable offence against Dutta under Section 500 (defamation) of the Indian Penal Code and are investigating the complaint. We have also asked the complainant to approach court," the officer said.

Dutta, 34, who has accused actor Nana Patekar of harassing her on the sets of a film in 2008, recently said Raj Thackeray wanted to succeed late Bal Thackeray as the Shiv Sena chief, but could not do so.

She had also alleged that the MNS was involved in vandalising her vehicle when she opted out of the 2008 film, Horn Ok Pleassss.

Dutta also alleged that she had been getting threats from the MNS, adding that two persons recently tried to barge into her home.

The MNS youth wing, meanwhile, handed over a letter to the makers of the Bigg Boss on Wednesday, following reports of Dutta participating in the ongoing season of the TV reality show, a party functionary told PTI.

The party workers threatened violence on the set in Lonavla if she was let in.

Maharashtra minister Deepak Kesarkar had backed Patekar on Wednesday, saying he was an "illustrious personality" who has done tremendous work for the state and questioned the veracity of Dutta's claims.