Police rescued neurosurgeon Dr Ramesh Chandra from Chiraura village under Naubatpur police station in Bihar early on Wednesday.
A gang patronised by the Samata Party legislator from Piro, Sunil Pandey, had abducted the doctor, Director General of Police D P Ojha said.
The abductors had demanded Rs10 million, but Dr Chandra was rescued without paying anything, he said.
Patna Senior Superintendent of Police, Sunil Kumar, said around six people had been arrested in connection with the abduction, which was carried out near Dr Chandra's residence in Mithapur locality of Patna on Saturday night.
The Indian Medical Association had threatened to paralyse medicare services in Bihar if Dr Chandra was not rescued by Wednesday.
"We have decided to call off our agitation in view of the release of Dr Chandra," IMA state general secretary Dr Sahajadanan said, adding all district units had been informed about the decision.
The National Democratic Alliance had also called a Patna bandh on Wednesday.
The Leader of the Opposition, Sushil Kumar Modi, said the Patna bandh had also been called off, 'but we will continue to agitate against the government's failure to check spiralling crime graph'.
At the Kotwali station in Patna, Dr Chandra said he was thankful to the police for his rescue.
Inspector General (Patna zone) A C Verma, SSP Sunil Kumar and city police Superintendent O N Bhaskar met Dr Chandra at the station before he was sent to his home under escort.
"I am too tired to talk about the details of my kidnapping and how I was treated by my captors," Dr Chandra said at his residence, where his relatives and neighbours had gathered.
Meanwhile, the Rashtriya Janata Dal and the NDA traded charged over the abduction.
"The facts available with the police suggest close links of (Union minister C P) Thakur with the criminal gang involved in the kidnapping," Minister of State for Health in the Rabri Devi government, Akhilesh Prasad Singh, said in Patna.
"I am not in the habit of making wild allegations against anybody, but the government and the police have information that the abductors had telephoned the residences of the Union minister and Samata party MLA Sunil Pandey after the kidnapping."
Among those arrested were men who had fired in jubilation at the Patna airport after Thakur became minister for the second time.
Thakur, however, dismissed the charge as 'baseless and designed to tarnish my image'.
He said, "RJD president Laloo Prasad Yadav and his ministers have been levelling such charges against me for a long time... this is part of dirty politics.
"I am also the local MP. A large number of people might have been jubilant at my becoming minister... That does not mean I have any links with criminals."
Thakur said the RJD government had tried to link him with the Ranvir Sena and the killing of dalits at Haibaspur village in rural Patna a few years ago.
"It is very clear that Laloo Prasad Yadav is using a fellow Bhumihars like Singh to speak against me... Singh is not the state's home minister so why should the police inform him about my so-called links with the kidnappers."
Thakur, himself a leading physician, said Dr Chandra was his friend.
The Union minister found an ally in Modi, who said: "A large number of RJD ministers and MLAs are criminals or have links with criminals..."