Under Indian law, a polygraph test can only be conducted with the subject's consent. Goyal's lawyer, Vipul Dusing, said the 20-year-old gave her consent to the Lonavala Rural Police on Thursday.

Police have also moved a court seeking permission to conduct lie detector tests on Goyal and her alleged lover and co-accused, 22-year-old Chetan Chaudhary.

Accused taken to alleged rehearsal spot

Earlier on Thursday, investigators took Goyal to a location in Pune's Lullanagar area where, according to police, she and Chaudhary had allegedly rehearsed how to push Agarwal off a cliff weeks before the murder.

"Investigation has revealed that Siya and Chetan had rehearsed at a hillock-like space near a club in Lullanagar how to push Ketan off the cliff at Lohagad Fort.

"Today, Siya was taken to the spot, where she identified the place where they had allegedly carried out the rehearsal," a Pune Rural Police official told the media.

Police said the rehearsal took place in May and are working to establish the exact date and sequence of events.

Clothes recovered, digital evidence under scanner

Investigators have also recovered clothes allegedly worn by Goyal on June 18, the day Agarwal was killed, during a search of her residence in Pune's Market Yard area.

Police said they have gathered a substantial amount of technical and digital evidence, which is currently being analysed and cross-verified.

Goyal and Chaudhary are accused of pushing Agarwal to his death at Lohagad Fort on June 18. The couple had been engaged and were scheduled to marry in November. Both accused remain in police custody until July 3.

What investigators hope to learn

Police are relying on polygraph examinations because there were no eyewitnesses to the alleged murder and the two accused have given conflicting accounts, each blaming the other for the fatal push.

The investigators are expected to use the tests to verify:

  • Who pushed Ketan Agarwal into the gorge.
  • Whether Goyal gave a pre-arranged signal before the alleged attack.
  • The extent of planning discussed during a meeting at a café a day before the incident.
  • Details of three alleged failed attempts and the rehearsal conducted near a hillock.
  • Whether Goyal deleted evidence from Chaudhary's mobile phone while it was in her possession.
  • The nature of her relationship with Chaudhary and whether she was unwilling to marry Agarwal.
  • A polygraph, commonly known as a lie detector test, records physiological responses such as blood pressure, pulse, breathing rate and perspiration while a subject answers questions.

The results are used only as an investigative aid and are not treated as conclusive evidence in court.