Mr Sinha, Lok Sabha member from Patna Saheb, according to a report by news agency IANS, said, "I've been hearing this threat of being expelled from the party for many years. Please stop threatening. Why don't you just expel me?"
Earlier this week, a Twitter war had erupted between the two when the actor had tweeted in favour of RJD chief Lalu Prasad and Delhi Chief Minister Arvind Kejriwal saying "enough of negative politics and mudslinging".
His remark drew a stinging reaction from Mr Modi who sought removal of "gaddars" (traitors) and "enemies of the party" from the party.
The 71-year-old, who is considered one of the most unconventional actors of Hindi cinema, shot back saying that the "BJP is being ruined by yes-men and sycophants who refuse to read the writing on the wall".
He also took this opportunity to blame Mr Modi for the BJP's defeat in the Bihar assembly elections in 2015. "Some people who are wholly & solely responsible for OUR party's debacle in Bihar r today crying hoarse,hoping to regain their lost image," he said in a tweet.
At that time, Mr Sinha had praised Bihar Chief Minister Nitish Kumar and had congratulated him and his partner Lalu Yadav when their alliance had defeated the BJP in the assembly elections.
(With inputs from IANS)