Mahmud was left blindfolded on the side of the Dhaka-Raipur road around 11:30pm on Wednesday, his father AKM Nurul Alam told reporters on Thursday morning.
He then took an autorickshaw to his home near the Motherland Hospital in Lakshmipur, he added.
It is not yet known where Mahmud was held or who kidnapped him.
Speaking to the media later, Mahmud said he was kept blindfolded with hands tied.
“They would only untie me when it was time to eat," he told reporters in Lakshmipur. “But, during all this time, they never tortured or interrogated me.”
Mahmud says he begged them to release him several times, but heard no response. “I would ask them why I had been held, but they just remained silent.”
Asked whether he was given enough food, Mahmud said: “I was satisfied with what they gave me. It is by Allah’s grace that I have been able to return.”
A doctor at the Comilla Medical College Hospital, Mahmood came to Dhaka last year for a two-month training programme at Bangabandhu Sheikh Mujib Medical University.
He was kidnapped near the Science Laboratory intersection on October 10 last year.
CCTV camera footage from the venue showed Iqbal’s kidnapping. The video showed a group of seven or eight men close in on Mahmood and shove him into a microbus at 3:10 am. A police pickup van could also be seen behind the microbus.
“I have spoken to Dr Iqbal. He is healthy,” Lakshipur Sadar Police Station OC Lokman Hossain toldbdnews24.com.