Irrfan, who played the role of CBI officer Arun Kumar in the film, took an entire month to get an insight of his character.
"#Talvar.. And @irrfan_k you are just terrific.. Undoubtedly you are one of the best actor we have... And you are my superstar too," Shoojit, who worked with Irrfan in "Piku", posted on Twitter.
The Meghna Gulzar-directed film, which released on October 2, was inspired by the sensational murder of 14-year-old Aarushi Talwar and 45-year-old Hemraj Banjade, a domestic help in Noida, India in 2008.
"Talvar" also starred Neeraj Kabi and Konkona Sen Sharma.