Jamnagar District and Sessions Court Judge D.M. Vyas also awarded similar penalty to police constable Pravinsinh Jhala.
The verdict came after the Supreme Court last week rejected Bhatt's application seeking fresh examination of witnesses in the case, contending that this was key to arrive at a proper judgment.
The ex-officer had challenged a decision of the Gujarat High Court against this plea. The state government had meanwhile submitted in the Supreme Court that the trial court had reserved its verdict for June 20.
Bhatt was an additional superintendent of police in Jamnagar district when the incident occurred in 1990 in Jamjodhpur. He had detained one Prabhudas Vaishnani along with 133 others for rioting and other offences during a bandh call given by the BJP and the Vishwa Hindu Parishad in the wake of arrest of BJP leader L.K. Advani during his Ayodhya Rath Yatra.
Vaishnani, who was allegedly severely beaten up in police custody, later succumbed to his injuries days after his release. His brother Amrit Vaishnani had lodged a complaint against Bhatt and five other policemen. The trial started in 2016.
The former police officer is at present lodged at Palanpur sub-jail in North Gujarat in connection with an alleged case of framing a lawyer for possession of drugs when he was Superintendent of Police in Banaskantha district.
Bhatt was arrested in September 2018.
Bhatt, who has always been at loggerheads with the BJP government in Gujarat, had deposed before various inquiry commissions after the post-Godhra riots of 2002 against then Chief Minister Narendra Modi. However, a Special Investigation Team (SIT) had given a clean chit to Modi.
The controversial officer was first suspended in 2011 for remaining absent from duty without proper permissions and subsequently sacked in 2015. Before his arrest last year, the Ahmedabad Municipal Corporation had demolished a portion of his house in Ahmedabad declaring it illegal.
His wife Shweta Bhatt had contested the 2012 Assembly election against Modi from Maninagar constituency in Ahmedabad and lost.
( With inputs from IANS )