Mumbai police arrested Mr Upadhyay on Tuesday after questioning him for several days.
Mr Upadhyay has denied any involvement in the murder of his wife and her lawyer.
The bodies of Hema Upadhyay, who was a well-known artist, and her lawyer were found in a drain on 11 December.
Senior police officer Dhananjay Kulkarni told the BBC that four others have also been arrested.
Reports said the estranged couple were going through bitter divorce proceedings. Mr Bhambani was representing Hema Upadhyay in the case.
She had also filed a harassment case against her husband in 2013, saying he was painting obscene images of women on the walls of their house in Mumbai.
The couple were known for raising social issues with their installations in India and abroad.
Indian artist Chintan Upadhyay has been arrested in connection with the murder of his estranged wife Hema and her lawyer Harish Bhambani.