Zimbabwe energy minister Elton Mangoma on Tuesday was cleared of charges that he breached tender regulations in a fuel deal.
"The state has failed to establish a prima facie case," Justice Chinembiri Bhunu said. "The accused is, therefore, found not guilty."
The verdict was greeted with cheers from supporters and family members in the gallery.
The judge said Mangoma could not be faulted for sourcing fuel when petrol shortages threatened to bring the country's fragile economy to its knees.
"During the period in question, there was an acute shortage of fuel in the country," the judge said.
"Virtually all state witnesses confirmed that there was no fuel at the material time."
Mangoma, a top aide of Prime Minister Morgan Tsvangirai, was accused of breaching tender regulations in the purchase of five million litres of diesel from a South African company when Zimbabwe's fuel reserves ran dry in 2009.
Zimbabwe's procurement laws prohibit government departments from buying goods worth more than $50,000 without going to tender.
His arrest and detention in March drew an angry reaction from Tsvangirai, who called for new elections and said it was time for a "divorce" in the unity government with veteran President Robert Mugabe.
Mangoma will appear in court on July 28 for trial in another case in which he is facing allegations of cancelling a tender for the supply of pre-paid meters to the state electricity company.