UPDATE 2-African billionaire returns home unharmed after release by kidnappers - police

Africa's youngest billionaire snatched a week ago off the street outside a luxury hotel in Tanzania, has returned home unharmed after being released by his kidnappers, police said on Saturday.

Mohammed Dewji, the 43-year-old CEO of the METL Group family conglomerate, was seized as he arrived for a morning workout in Tanzania's commercial capital Dar es Salaam last week. Forbes estimates his net worth as $1.5 billion, making him Africa's 17th richest man and its youngest billionaire.

Lazaro Mambosasa, Dar es Salaam's police commander, told Reuters that Dewji was abandoned by his kidnappers in the city's Gymkhana area at 2:30 am local time.

Dewji had been held in a house in an area where police were about to conduct a house-to-house search, he said.

"He was tied legs, hands and face, therefore, he could not see. He could not identify the abductors throughout the period of captivity," Mambosasa said. He had only bruises on his hands and feet where they were tied.

"He told us that they treated him very well and gave him food," he said.

Dewji's family had offered a reward of 1 billion Tanzania shillings ($440,000) for information leading to his release, though it was not immediately clear how much the kidnappers had demanded.

Speaking at a news conference, Inspector General of Police Simon Sirro said Dewji had told them the suspects spoke in English and "broken Swahili" and that a vehicle they had travelled on had foreign plates.

"The good thing is that we are communicating regularly with our colleagues at Interpol," he told reporters.

Four weapons, including an assault rifle and numerous bullets, were found in the car, which was partially damaged in a botched attempt to destroy evidence, Sirro said.

On its Twitter feed, METL Group quoted Dewji as saying he had "returned home safely", without providing more details about how he was freed or got away from his captors.

The company also quoted him thanking those who had worked for his release, including the police.

His abduction had caused consternation in the East African nation as he is one of its most prominent business executives and had been a member of parliament in the past.

METL Group is involved in a diverse range of manufacturing, farming, transport, infrastructure, agro-processing and telecoms businesses spanning 11 African countries. 

(With inputs from agencies.)