"I thank Allah that I have returned home safely", said a statement released by Mohammed Dewji's foundation. The businessman thanked Tanzanian police "and everyone around the world for their prayers".
Speaking at a news conference, Inspector-General of Police, Simon Sirro, said Mr Dewji had told them the suspects spoke in English and "broken Swahili" and that a vehicle they had travelled on had foreign plates.
Mr Dewji's family had offered a reward of one billion Tanzania shillings (S$600,000) for information leading to his release, though it was not immediately clear how much the kidnappers had demanded.
Gullam Dewji, Mr Dewji's father, told...
In a message on his Twitter, Africa's youngest billionaire confirmed the news to his followers after he was abducted by "white gunmen" nine days ago in Dar es Salaam, Tanzania's capital. Dewji, who attended the news conference in a white T-shirt and trousers, thanked police officers and shook their hands.
"He told us that they treated him very well and gave him food", Mambosasa said.
"They fired a gun and then they opened the gate", area police boss said on the day of the arrest.
"We now know their network, we know which country the plans were made", he reportedly said, without expanding futher.
"He has tied legs, hands and face therefore he could not see".
Dewji owns MeTL Group, a conglomerate operating in several African countries and contributing about 3.5 percent to Tanzania's gross domestic product, according to its website. He also served as a member of parliament from 2005 to 2015.
In 2013, he became the first Tanzanian to be featured on the cover of Forbes magazine.
Mohammed Dewji is also the main shareholder in Tanzania's Simba FC football club.
According to Forbes he is 17th on the list of Africa's billionaires, and worth $1.5 billion (£1.14 billion).