Tanzanian police said Friday they had identified the driver of a vehicle used in the kidnapping of Tanzanian billionaire Mohammed Dewji, who was snatched over a week ago.
Dewji, 43, who is considered Africa's youngest billionaire, was seized by gunmen as he entered a hotel gym in Tanzania's economic capital Dar es Salaam Thursday morning last week.
His family is offering a reward of half a million dollars (435,000 euros) for information that would help police find him.
Police chief Simon Sirro told a press conference that surveillance videos at the hotel had captured images of the vehicle used by the kidnappers, a dark blue 4X4.
"We have been able to identify the vehicle. So we have advanced a lot in our investigation, we will publish these photos," he said.
"On top of that we know this car entered the country on September 1 from a neighbouring country," Sirro added, refusing to name the country.
"We already have the names of the vehicle's owner and the driver."
Sirro said he would send Tanzanian police to the neighbouring country in question, without giving any details.
He said that of 27 people arrested eight were still in custody.
The opposition has called for independent international investigators to take over the probe, citing an increase in kidnappings and attacks in which no one is ever brought to book.
Dewji is chief executive of the MeTL Group, which operates in a dozen countries and has interests in agriculture, insurance, transport, logistics and the food industry.
According to Forbes, he is worth $1.5 billion (1.29 billion euros) and ranks 17th on the list of African billionaires.
He was a member of parliament from 2005 to 2015, and in 2013 became the first Tanzanian to feature on the cover of Forbes magazine. Two years later, he was named Forbes' Africa Person of the Year.
Dewji is also the main shareholder in Tanzania's Simba FC football club.