Mohammed Dewji, owner and president of the multibillion-dollar revenue Mohammed Enterprises Tanzania Ltd (MeTL Group), was abducted after he arrived for a morning workout at a luxury hotel in the country's commercial capital.
Three people have been arrested in connection with the incident and two of the abductors were believed to be foreign nationals, police added.
The police boss said the suspects fired in the air as they drove away with Mr Dewji.
A normally sleepy city, Dar es Salaam is not known for high intrigue, and there has certainly never been a case of white men kidnapping prominent individuals reported before.
Dewji was born in Tanzania and studied at Georgetown University in the United States.More news: Samsung Galaxy A9 Quad-Camera Mid-Range Phone Image And Benchmarks Leak
He served two terms in the Tanzania parliament before he resigned in 2015 to dedicate more time to the family business.
Dar es Salaam regional commissioner Paul Makonda cautioned the public against speculation.
Mohammed Dewji, a Tanzanian business tycoon said to be Africa's youngest billionaire, photographed during an interview at his office in Dar es Salaam, Tanzania, April 23, 2015.
According to Forbes, he is Tanzania's sole billionaire with a net worth of $1.5 billion.
Dewji runs MeTL, a multi-establishment company operating in six African countries which was founded by his father in the 1970s.
In 2016, Dewji signed The Giving Pledge in 2016 and promised to donate at least half his fortune to philanthropic causes.