The Delhi Police yesterday recovered the knife, allegedly used by Major Nikhil Handa to slit the throat of a fellow Army officer's wife, from a spot near the Meerut-Muzaffarnagar highway.
Traces of burnt clothes were also recovered from the spot, the police said.
The investigators also found a lot of pornographic material on Major Handa's cell phones. However, the accused had deleted his chat record and the messages exchanged with the victim, Shailza Dwivedi, the police said, adding that the phones will be sent for a forensic examination.
Shailza Dwivedi's phone, which was broken by the accused, will also be sent for a forensic examination, though an officer said chances of data recovery were slim since its motherboard was badly damaged.
A senior officer, privy to the probe, said a CCTV grab showed that while going towards Meerut, the accused had taken a detour on the Meerut-Muzaffarnagar highway.
The accused was questioned about it and he led the police to the spot, where he had dumped the knife he had bought from Sadar Bazar, the officer added.
The police also recovered the clothes of the accused that he had burnt and will be sending those for a forensic examination, he said.
The police custody of the accused ends today and the investigators are not likely to seek an extension in the court.
The victim's body was found with its throat slit near the Brar Square in the Delhi Cantonment area on Saturday.
Initially, the police were informed that a woman had died in an accident, but later, when they inspected the body, it was found that the throat was slit.
The accused had allegedly run his car over the victim's face and body in order to make the incident appear as an accident.
The accused was arrested from Meerut on Sunday.