A Zimbabwean judge has dropped charges of treason against the secretary general of the opposition Movement for Democratic Change, Tendai Biti.
He had faced a possible death sentence after being accused of plotting a coup against President Robert Mugabe.
But Magistrate Olivia Mariga said prosecutors appeared unprepared to proceed against Mr Biti.
It could be a sign that the ruling Zanu-PF wants a proposed coalition government to work, say correspondents.
The decision was announced the day after parliament unanimously passed a constitutional amendment, creating the post of prime minister for opposition leader Morgan Tsvangirai.
We are going to finish this job that we started of removing the dictatorship of Robert Mugabe
President Robert Mugabe is expected to sign the bill into law shortly.
The MDC also wants all of its jailed supporters and activists to be freed before Mr Tsvangirai takes office.
Ms Mariga also ruled Mr Biti had been improperly arrested when he was detained in June, in part over a document purporting to lay out opposition plans to overthrow the government.
The document has since been widely dismissed as fraudulent.
But Ms Mariga said prosecutors could still revive the case by issuing a summons.
Mr Biti said he was happy at the court's decision and remained defiant.
"We are going to finish this job that we started of removing the dictatorship of Robert Mugabe."