Mumbai, Dec 22 (IANS): In a dramatic twist in the double murder of artist Hema Upadhyay and her lawyer Harish Bhambhani, police early on Tuesday arrested the victim's estranged husband Chintan Upadhyay, an officer said.

He was summoned by Kandivali Police late on Monday, subjected to interrogation and finally arrested around daybreak.

A reputed artist himself, Chintan was earlier questioned by police several times in connection with the murder in which four persons have already been arrested from Mumbai and Varanasi.

The victims' kins, including his brother-in-law Deepak Prasad (Hema's brother), have pointed fingers at Chintan who had allegedly threatened Hema with death a few years ago.

Chintan will be produced before a magistrate later today for remand, an official said.

Last week, police nabbed four other prime accused -- Satyaprakash alias Sadhu Rajbhar, Pradip Rajbhar, Azad Rajbhar and Vijay Rajbhar -- in connection with the double murder, while another Vidyadhar Rajbhar is still absconding.

Police believe that the four Rajbhars helped Vidyadhar Rajbhar in committing the murders and in disposing off the victims' bodies in a Mumbai suburb's drain last weekend.

The barely-clothed bodies of Hema and Bhambhani were packed in cardboard boxes, wrapped in plastic sheets and thrown in a large open drain near Dahanukarwadi in Kandivali West, a suburb in north-west Mumbai.

The boxes with the bodies, recovered on December 13, were transported in a tempo from Juhu to Kandivali, police said.

The motive behind the murders is still not clear, but police said Hema Upadhyay and her husband Chintan Upadhyay, married in 1998, were in a divorce battle for the past five years.