The 25-year-old victim, Supriya Singh, got married to Palghar district's Vasai area resident Chandan B Singh (28) in March 2013. At the time of her wedding, the woman's parents gave Rs 5 lakh to her in-laws as dowry, Thane's Mira Road police sub-inspector P S Salunke said.
However, soon after marriage, Supriya's husband and in-laws started harassing her. They allegedly beat her and abused her while demanding more dowry, he said.
Fed up with the constant harassment, the woman hanged herself at her house in Nallasopara area of Vasai on September 16, he said.
Based on the complaint, Mira Road police arrested the woman's husband Chandan B Singh, brother-in-law Pawan B Singh, father-in-law Beechu Singh and mother-in-law Shail Beechu Singh last evening.
Supriya's sister-in-law Soni Singh, who is also an accused in the case, is absconding and police have launched a search to nab her, Salunke said.
The accused have been booked under sections 304B (dowry death), 306 (abetment of suicide), 498A (husband or relative of husband of a woman subjecting her to cruelty), 406 (criminal breach of trust), 323 (voluntarily causing hurt), 504, and 506 (criminal intimidation) read with 34 (acts done by several persons in furtherance of common intention) of the Indian Penal Code, he added.