"By the time the FBI lab got the viscera samples, the contents had already degraded. There was an unnecessary delay on part of Delhi Police in sending the viscera samples of Pushkar to FBI," AIIMS Forensic Science department head Sudhir Gupta said.
The Washington DC-based FBI lab had last week endorsed the AIIMS' claim of poisoning as the cause the death of Pushkar, wife of Congress leader Shashi Tharoor, and also said a "dangerous chemical" present in her body might have killed her.
Later, Gupta also said the death was due to poisoning as was concluded by the AIIMS. He, however, claimed FBI did not rule out completely the presence of radioactive substances in viscera samples.
"...But due to degraded condition of the viscera samples, they could not read the intensity of the substances," he contended.
Gupta had earlier alleged pressure on him to dilute the investigation and claimed the previous government, with the help of the AIIMS administration, tried to remove him from his post in a bid to form a medical board which would have given a natural death report.