The man said to be Africa's youngest billionaire has been kidnapped by masked gunmen in Tanzania's main city Dar es Salaam, police say.
Mohammed Dewji, 43, was abducted outside a swanky hotel gym where he was going for his routine morning workout.
Three people have been arrested in connection with the incident and two of the abductors were believed to be foreign nationals, police added.
The motive for Mr Dewji's abduction is still unclear.
Financial magazine Forbes puts his wealth at $1.5bn (£980m), and has described him as Tanzania's only billionaire.
In a 2017 report, it said Mr Dewji was Africa's youngest billionaire.
Mr Dewji is also a major sponsor of one of Tanzania's biggest football teams, Simba.
He promised in 2016 to donate at least half his fortune to philanthropic causes, Forbes said.
Mr Dewji, locally known as Mo, is credited with turning his family business from a wholesale and retail enterprise into a pan-African conglomerate, reports the BBC's Athuman Mtulya from Dar es Salaam.
His company, MeTL, has interests in textile manufacturing, flour milling, beverages and edible oils in at least six African states.
Mr Dewji served as a ruling party MP for a decade until 2015. He told the BBC in a 2014 interview that this possibly made it easier for him to meet top politicians, but it did not give him an unfair advantage, as other businessmen also had access to them.
Environment Minister January Makamba, a friend of Mr Dewji, tweeted that he had spoken to Mr Dewji's father and the family confirmed that he had been kidnapped.
By Caroline Lewis, former MeTL employee
Mohammed Dewji has huge celebrity status in Tanzania. You would be hard pressed to find a person in Dar es Salaam who did not know of Mohammed or the Dewji family and he would often draw large crowds at public events.
But despite his wealth and fame he has always been incredibly relaxed in his approach to security - in fact all the Dewji family were.
He never moved with security guards or bouncers and would often pop out to the gym on his lunch break or to meet friends after work unaccompanied.
In his day to day life he didn't look like a billionaire - he was a friendly, affable young man going about his business.
The abduction took place in the affluent neighbourhood of Oysterbay.
The kidnappers fired shots in the air before driving away with the billionaire, eyewitnesses said.
Police officers inspect Mohammed Dewji's vehicle after his abduction
Mr Dewji, a fitness enthusiast, had no security guards with him and had driven to the gym on his own, Dar es Salaam regional police commissioner Paul Makonda told reporters.
Two of the kidnappers were white men, he added.
Security personnel across Tanzania have been put on high alert in the hunt for the abductors, police said.
By Athuman Mtulya, BBC Africa, Dar es Salaam
The city's name comes from Arabic, and literally means Abode of Peace. And Dar es Salaam is very safe, in comparison to Lagos or Johannesburg, the main cities in Nigeria and South Africa respectively.
Although Tanzania has seen a wave attacks and abductions of opposition politicians and perceived government critics, this is the first time a businessman of Mr Dewji's standing has been kidnapped in the country.
Businessmen have never felt at risk of being kidnapped and they often move around on their own. Some may have chauffeurs, but not bodyguards. So Mr Dewji's abduction has come as a huge shock.