"Just lodged a complaint with the Versova police against the BJP Yuva Morchas threat to me on the Maria Susairaj issue," Varma, who is planning his next film inspired by the Neeraj Grover murder, posted on his Twitter page.
"Other organizations warnings I got to hear from the media but the BJP (Bhartiya Janata Party) sent a signed warning letter directly to my office," he added.
After the verdict in was announced last week, Varma had quickly announced that he wanted to cast Susairaj in "Not a Love Story", and now he has defended this decision as well.
"If smone hs been convicted and the person servd a gvn sentence she has a right to start her life afresh nd thts a part of civilized society," posted Varma.
"Maria is nt my sister or my girlfriend nd I don't evn knw her..so its nt about supporting her but its about standing fr my beliefs," he added.
On Monday, the Mumbai units of the Bharatiya Janata Party (BJP), Shiv Sena and Maharashtra Navnirman Sena (MNS) had warned filmmakers and TV channels against casting Susairaj in any of their ventures.
Varma wonders why some people are creating a fuss after the court has given its verdict.
"Evn aftr court gave its judgment if even the least informed ppl are raising so much noise doesn't it come under contempt of court," he posted.
"Public opinion is fine but isn't there a difference btwn opinion and an informed opinion? nd who can be more informed than the judge," he added.
Last week, former naval officer Jerome Mathew was awarded 10 years in jail after a Mumbai court found him guilty of culpable homicide not amounting to murder in the killing of Neeraj Grover in 2008.
His fiancee Susairaj was given a three year jail term for destroying evidence. A struggling actress, she walked out free from jail two days ago as she has already served the sentence as an undertrial.