The video was shot on May 4 and had surfaced earlier this month.
The Manipur Police has got in touch with the two women, who were paraded naked in May and then sexually assaulted, and is in the process of recording their statements, officials said here on Friday.
They said keeping in mind the situation arising out of ethnic clashes that broke out in the state on May 4, a team of women officials and personnel from Manipur police was formed to probe the case.
The officials said the team had met the family members as well as the two women and the process of recording their statements has begun.
The process of identifying eyewitnesses and recording their statement has also begun, they added. The cases pertaining to the sexual assault have been handed over to the CBI.
Reacting to the arrest of people in the viral video case, spokesperson of the Indigenous Tribal Leaders Forum (ITLF) Ginza Vualzong termed it "too little, too late".
"I would have appreciated it if the culprits were arrested before the video went viral. The FIR was registered on May 18. There are many more such cases. Having said that, I would also like to clarify that arresting people would not solve the larger issues of the state which has been witnessing ethnic clashes," Mr Vualzong said.
"I request the Centre to take the Manipur issue seriously and take steps to end the violence and come up with a solution," he added.
Police have arrested seven people, including a juvenile, in connection with the case so far.
Police had registered a case of abduction, gangrape and murder at Nongpok Sekmai police station in Thoubal district against unknown armed persons.
The video which drew widespread condemnation shows men molesting the two helpless women, who cry and plead with their captors to spare them.
Prime Minister Narendra Modi and Chief Justice of India D Y Chandrachud had expressed deep anguish and called the incident "shameful" and "unacceptable".
Manipur has been witnessing ethnic clashes since May 3. Over 150 people have been killed in the violence so far.
Manipur Chief Minister N Biren Singh had said he will ensure strict action is taken against all the perpetrators, including considering the possibility of capital punishment.
"My heart goes out to the two women who were subjected to a deeply disrespectful and inhuman act, as shown in the distressing video that surfaced yesterday," Mr Singh had tweeted.
"A thorough investigation is currently underway and we will ensure strict action is taken against all the perpetrators, including considering the possibility of capital punishment. Let it be known, there is absolutely no place for such heinous acts in our society," he said.
Meiteis account for about 53% of Manipur's population and live mostly in the Imphal Valley, while tribals, which include Nagas and Kukis, constitute 40% and reside mostly in the hill districts.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)