A fresh probe has been launched into the incident from April in light of the development.
Legal experts point out that with the State Lab losing the NABL accreditation, the authenticity of their forensic examination reports gets challenged in the courts.
The plastic bottle containing petrol suddenly caught fire killing T V Prajith and his wife K K Reesha, states the report.
Rat poison, in the form of paste, apparently affected her liver, which resulted in the death.
Crime Branch officials want to confirm whether the letter which appeared in the Mayor Arya Rajendran's name and addressed to CPM' Thiruvananthapuram district secretary Anavoor Nagappan was prepared on the seized computers.
The Crime Branch action comes amidst allegations that it is going slow on the probe into the letter row.
An official also said that police have seized Sharma's co-actor Sheezan Khan's mobile phone and clothes which he wore on the day of the incident.
Swamy, 84, who was an accused in the Elgar Parishad-Maoist links case, died in July 2021, while waiting for interim bail on medical grounds.
The court has directed to complete the analysis within 7 days. The results of the forensic examination would be available to the trial court and the probe officer.
The prosecution also reiterated that actor Dileep, the eight accused in the case, is in possession of the copy of the visuals.