Police spokeswoman Charity Charamba could not confirm whether Mugabe was travelling in the motorcade, but said the accident happened in the posh Harare suburb of Borrowdale, where Mugabe's private residence is located.

"The accident was fatal involving a T-35 truck around 10:00am this morning," said Charamba.

National radio reported that the officer was a lead rider in the presidential motorcade, and that he crashed as the motorcade was heading towards the city centre.

No one else was injured.

In June, one person was killed by Mugabe's motorcade just outside the president's rural home in Zvimba, in the northwest of the country.

In the same month, a motorbike in the presidential cavalcade hit and killed a mentally disabled man, a member of the presidential guard and seven others were also killed when a truck in the motorcade overturned after a tyres burst.

Mugabe typically travels with an escort of around 10 vehicles, including the presidential limousine, a Mercedes Benz, motorcycles and army vehicles.