The body parts were found inside the suitcase which was carrying on the Tamil Nadu Express to Agra, and have since been kept under the protection of authorities at a government hospital there.

The police are now planning to bring the body parts to Chennai for further examination and DNA testing as part of efforts to formally establish the identity of the victim and gather crucial evidence in the murder case. Also, the red suitcase, an important piece of evidence in the investigation, is required to be produced before the court as part of the case records.

The victim, Nisha (38), a woman from north India, had been staying in a rented house in Guduvanchery and working at a private company in Tambaram. She was murdered on August 3. The accused, Manik Uddin Laskar (22) and his wife, Bagamathi Maji (20), both from north India, were arrested by the special police team from Manipur and brought to Guduvanchery for interrogation.

During the investigation, the police took the accused to the house where the murder took place and made them recreate the crime. The investigators also seized weapons, including scissors and a large knife used for cutting meat.

The accused were taken to MGR Chennai Central railway station, where they were made to recreate how they carried the suitcase onto the Tamil Nadu Express and left it on the train.

Officials said the accused had watched YouTube videos to learn how to carry out the murder. Meanwhile, the police had been searching for Nisha's severed head for several days but were unable to locate it.

With the next phase of the investigation now under way, officials are expected to transport the suitcase and the dismembered remains to Chennai within the next couple of days and hand them over to the Guduvanchery police special team for further investigation and DNA analysis.