Manu Kumar Srivastava (25) of Lucknow smiled after many moons when he got bail on Monday following 20 months in a Muzaffarpur jail on the charge of a motorbike theft.

While the investigating officer could not corroborate the charge against Manu, 20 months in judicial custody have left Manu in such a condition that the jail superintendent had recommended he be treated for his mental health.

Manu could not hide his joy after S.K. Tripathy, judicial officer at a Muzaffarpur court, accepted his bail petition and allowed his release from judicial custody. "I want to get out. I want to go home, to my village Alamganj (under Krishnanagar police station of Lucknow district in Uttar Pradesh)," Manu told his lawyer Sushil Kumar Singh, who has provided him legal aid free of cost all these days.

"I am thankful to my advocate, who appeared on my behalf and pleaded my case. Had he not done so, I would have had to spend more time in judicial custody," Manu, who lost his parents in a train accident, said before leaving for his native place on Tuesday.

His lawyer, Sushil, said a police team had arrested Manu from an area under the jurisdiction of Ahiyapur police station in Muzaffarpur district, around 80km north of Patna, on January 1 last year.

He was booked under sections 414 (theft) and 401 (owing allegiance to a gang) of Indian Penal Code. Though Manu tried to convince investigating officer Jango Ram that the bike he was riding was his own, the police took him to be a member of a bike-lifters' gang and submitted a chargesheet on March 5, 2014.

According to his lawyer, Manu was so depressed following his arrest and detention in judicial custody he started behaving abnormally at Khudiram Bose Memorial Central Jail. When the jail superintendent got to know of it, he wrote to the court requesting permission for his treatment at a mental health institute in Koilwar. "Since nobody could do pursue the matter on Manu's behalf, he could not be provided treatment at the mental hospital," Sushil said.

A Lucknow-based relative of Manu said his behaviour remains abnormal. Manu lost his parents in a train accident about five years ago.

"I have no idea how he fell in the police trap in Bihar," Manu's relative said on condition of anonymity. Lawyer Sushil said that Manu's is not an isolated case. Janhit Manch, a non-government organisation that fights for the cause of the poor pro bono (without payment), is providing free legal aid to 20 such prisoners lodged in the central jail in Muzaffarpur alone.

When contacted, investigating officer Ram said he had written to Lucknow transport department officials seeking details of the vehicle seized from Manu. "The report is still awaited," he said.

The prison directorate recently reviewed cases in which prisoners needed legal assistance.

During review, it came to the fore that several prisoners remained in custody either because they were unable to show property or savings for the bail bond, or because the police have not been able to verify their correct address for their release on a personal bond.