A non-cognisable (NC) offence was registered against an unidentified person after actress Sapna lodged the complaint through her manager at Amboli police station yesterday, they said.
She has claimed in a complaint that the caller threatened her of dire consequences if she spoke out against Bhatt and Malik, they said.
According to Sapna, while giving an interview to a local publication, she had said that Bhatt was a "porn director" and Malik was doing publicity stunts here and should be sent back to Pakistan.
Sapna is playing a lead role in the upcoming film "No 1 Dirty Heroine Sapna" and is also a producer.
Bhatt and Malik were not available for comments.