BJP leader Sonali Phogat was fed some "obnoxious chemical" through her drinks by the two accused during a party at a North Goa restaurant which apparently caused her death, police said on Friday.

The motive behind her murder could be "economic interest", said a senior police official.

Sudhir Sagwan and Sukhwinder Singh, named as accused in the case related to Phogat's `murder', were her associates and had arrived in Goa with her on August 22.

They have been detained by Goa Police and would be arrested soon, said Inspector General of Police Omvir Singh Bishnoi. Both the accused were seen mixing some obnoxious chemical substance in the liquid which was fed to Phogat twice, he said.

The incident took place at Curlies Restaurant at Anjuna in North Goa district on the intervening night of August 22 and 23, Bishnoi said.

Sagwan and Singh confessed during questioning that they had intentionally mixed the substance in her drinks, he said.

The motive behind killing her could be some economic interest, the IGP said.

The two men were seen taking Phogat to the washroom of the restaurant around 4.30 am on August 23 and the three of them were inside the washroom for two hours, he said.

Custodial interrogation will throw light on what happened during those two hours, Bishnoi added.

Two other women were also with the accused at the party and were seen cutting a cake, he said, adding that both were being questioned. Asked about the "multiple blunt force injuries" on her body mentioned in the post-mortem report, Bishnoi said as per the accused these could have been caused by abrasion while she was being taken to the hospital.

When she was taken to the hospital, there were no visible injuries, hence the doctors suspected that she died due to a heart attack, the IGP said.

But Phogat seemed to have actually died due to the substance she was fed at the restaurant, he said.

Police will also record the statement of taxi drivers who ferried her from Curlies restaurant to the hotel where she was staying and later to the hospital, Bishnoi said.

More people were supposed to join Phogat and others from Mumbai, the police official said.