A close ally of Zimbabwean Prime Minister Morgan Tsvangirai remains jailed, despite a Harare court's order that he be released.
A judge ordered Energy Minister Elton Mangoma to be on released on bail Tuesday, pending his trial on corruption charges filed last week.
But prosecutors then invoked a strict clause of the criminal law statues requiring suspects to remain in custody while their case is investigated.
Mangoma's detention prevented him from casting a ballot during a critical vote in parliament Tuesday for a new speaker.
Mangoma is a member of the Movement for Democratic Change, which shares power in Zimbabwe's unity government with President Robert Mugabe's ZANU-PF party.
MDC says Mangoma's arrest is part of a ZANU-PF harassment campaign.
The energy minister was arrested on one other occasion this month, also on corruption charges. He has denied the charges in both cases.
ZANU-PF was forced into a power-sharing government MDC after the disputed presidential election in 2008. Since then, the longtime rivals have been at odds and the country's political future remains uncertain.
Mr. Mugabe has called for elections later this year over the objections of Prime Minister and MDC leader Morgan Tsvangirai, who says Zimbabwe must first ensure that conditions are in place for a free and fair election.
Some information for this report was provided by AP, AFP and Reuters.