Hassan Onal, 45, was released on Sunday unconditionally, said Assad Allah Khan Khalid, the governor of Ghazni province southeast of Kabul. He had been kidnapped in neighbouring Zabul province.
“He is with the Afghan government and we will hand him over to the Turkish embassy," said Khalid.
A government official in Kabul and Onal's Turkish company confirmed he had been freed.
Friends who had seen Onal said he appeared to be in good health. "But after 32 days, he must be mentally exhausted," said Kurtulus Ergin, Kabul manager of Onal's firm Gulsan/Cukurova.
Ergin said no ransom had been paid and no deal done for his release.
Released as Muslim
“I don't want to speculate, but maybe the reason that they let him go is that he is a Turk and Muslim," he said.
Mullah Roazi, who described himself as the senior Taliban official in Zabul province, confirmed this.
“The main reason we decided to release this engineer is that he is a Muslim," he said.
Roazi said Taliban leaders, including former Defence Minister Mullah Obaid Allah and Mullah Beradar, decided to free Onal after the government freed two Taliban prisoners from Ghazni during last week's Eid holidays.
Onal and his Afghan driver were abducted at gunpoint while working on a US-funded road project in Zabul. The driver was freed the next day with a demand for the release of six Taliban prisoners.