The video shows 28-year-old Danielle McLaughlin being followed by a man who she appears to turn towards, in the southern state of Goa - a popular tourist destination for UK tourists.
The short clip was released after the dual British and Irish citizen was found dead on Tuesday in the resort of Canacona.
It comes after a 24-year-old man appeared in court on Wednesday charged with her murder.
A police officer involved with the investigation told the BBC that they believe they have caught the “main culprit” and that he had “confessed”.
Inspector Uttam Desai is quoted as saying: “He claimed he was totally drunk and does not remember much after the murder.”
The CCTV footage reportedly shows Danielle with the man arrested. In addition to the video, police said they found blood on the suspect’s scooter.
McLaughlin grew up in Buncrana, County Donegal, in the Republic of Ireland and had travelled to India in February.
She was found with extensive injuries to her face and head.
McLaughlin was identified with help from foreign tourists and information from social media.
Her mother Andrea Brannigan said McLaughlin would be “sadly missed by all”.
“The family would like to express our thanks to all who have got in touch since receiving this awful news,” she said.
“As you can expect we are finding it very difficult at this trying time.
“We want to thank the Irish and British consulates who, along with Colin from the Kevin Bell Repatriation Trust, and many friends who have assisted at this time.
“Danielle will be sadly missed by us all”.