"They have been arrested from their residences in Khed and Kondwa areas of the city today and charged with Indian Penal Code Sections 306, 34 pertaining to abetment to suicide, common intent, etc," investigating officer R.A. Patel of the Deccan Gymkhana police station said.
Those nabbed include his widow Priyanka Atul Tapkir (30), and her adopted brothers Kalyan Gavhane and Balu Gavhane.
The arrests follow a complaint lodged against them on Monday by Bajirao Tapkir, Atul's father. The arrested would be presented before a court later in the day, Patel said.
On May 14, Tapkir, 35, posted a 'suicide' note on Facebook before consuming a poisonous substance and ending his life in a locked room of Hotel President in the posh Deccan Gymkhana area of the city.
After the post went viral, the hotel authorities summoned the police, who broke open the room door to recover his body lying on the bed.
In his 'suicide' post, Tapkir had blamed his wife and the two Gavhane brothers for his extreme step, saying she constantly quarreled with him and threw him out of their home six months ago and kept him from meeting their children.
He also accused the Gavhane brothers and some others of threatening and thrashing him at his wife's instigation, which was also corroborated by his father Bajirao Tapkir in his police complaint.
The Pune police, in a related development, are also probing allegations against an official who reportedly took a bribe from Tapkir for not arresting him after his wife earlier lodged a complaint against him.
The co-producer of a 2015 film, "Dhol Taashe", which ran into losses, Tapkir had urged Maharashtra Chief Minister Devendra Fadnavis that "the police must listen to a man's side of the story too when a woman lodges a complaint".
He said his last wish was that since his wife cannot look after their children, his father should raise them.