Prasad, who is serving jail sentence in fodder scam cases, boarded the Rajdhani Express from Delhi last evening after doctors at the All India Institutes of Medical Sciences (AIIMS), where he underwent treatment for various ailments over the past one month, discharged him, citing "significant improvement" in his condition.
The former Bihar chief minister was taken to RIMS as soon as he alighted from the train around 10 am, said a police officer at the Ranchi railway station.
A medical team, constituted to look after Prasad, collected his blood samples for pathological tests after he was admitted to the cardiac ward, a doctor at the hospital said.
"A team of five doctors -- Umesh Prasad of the medicine department, R G Baxla of the surgery department, Prakash Kumar of the cardiology department, Bindu Bhusan Sinha of the eye department and Ashraf Jamal from the Urology department -- are looking after Prasad.
They are waiting for his reports to arrive to decide on the further course of action," he said.
In an official statement yesterday, AIIMS had said, "Lalu Prasad was referred from the Ranchi Medical College to AIIMS for management of his acute medical condition. He has improved significantly and as per advice of the medical board constituted for his treatment, he is being referred back to the Ranchi Medical College."
Prasad, however, alleged a "political conspiracy" behind his discharge.
In a letter to the director of AIIMS, the RJD supremo had said yesterday that doctors should not act under pressure from "certain individuals or political parties".
Prasad has been convicted in four fodder scam cases since 2013 - the latest being the Dumka treasury case, in which a special CBI court sentenced him to 14 years in jail.