Dr Munaf Tareen, in his late 60s, was released by his captors in Welpat in Bela, a deserted area, about 60 kilometres from Othal.
He had to walk for about six kilometres to reach Bela police station.
"Dr Munaf Tareen is sick and his feet are bruised," District Police Officer (DPO) Lasbela Ahmed Nawaz Cheema said.
"He has been shifted to Karachi for medical attention and then will be taken back to Quetta," he was quoted as saying by the Express Tribune.
More From This Section
The doctor, who spent over two and a half months in captivity, was abducted by armed men from Quetta's high security zone Pishin Stop on September 17 this year.
The Pakistan Medical Association (PMA) had been pressing authorities for Dr Tareen's quick recovery and holding protests on roads and were observing a boycott of government run hospitals in Quetta and other parts of Balochistan against his kidnapping.
"The kidnappers had severely tortured Dr Tareen and kept him in a dark room. We did not talk in detail but he is not completely stable now," Dr Dawood, a close relative of Dr Tareen told reporters.
A doctor on the condition of anonymity confirmed that Dr Tareen's family has paid a large amount of money as ransom for his safe release.
"The release took place because the kidnappers were paid money in millions," he stated.
He further claimed that the kidnappers had first demanded Rs 200 million, however, the amount was decreased later.
"Supreme Court assured us on November 27th that cardiologist will be recovered within few days," said Dr Faiz Hashmi, General Secretary PMA.
The doctors have been boycotting OPDs throughout the province for 17 days.
Kidnapping of doctors in Quetta remains a constant threat.
Gunmen had earlier kidnapped a well-known psychiatrist Dr Ghullam Rasool, Dr Saeed Ahmed Khan and other doctors and set them free later only after receiving heavy ransom amounts.