The MDC says the charges facing Mr Bennett are trumped up
Police in Zimbabwe have arrested a magistrate who ordered the release of MDC ministerial nominee Roy Bennett.
Other magistrates in the town of Mutare have gone on strike in solidarity with Livingstone Chipadze, officials say.
"It is frightening if a magistrate is arrested because he has passed a judgment that is not popular with the state," Mr Bennett's lawyer said.
Mr Bennett remains in custody. He was seized on the day MDC ministers joined a power-sharing government.
He is accused of links to an alleged plot to kill President Robert Mugabe.
But the Movement for Democratic Change (MDC) says the arrest is a political manoeuvre by hard-line supporters of Mr Mugabe to destabilise the unity administration.
Zimbabwean journalist David Farira in Mutare, on Zimbabwe's eastern border, says Mr Chipadze faces charges of criminal abuse of office.
Magistrate Chipadze is accused of improperly allowing Mr Bennett's lawyers to post bail of $2,000 and complying with other bail conditions on Tuesday.
2000: Elected MP
2004: Jailed after pushing minister in parliament
2006: Accused of plot to kill President Mugabe
2006: Fled to South Africa
2009: Nominated as deputy agriculture minister
After the bail money and his passport had been deposited with the Clerk of Court, a warrant to free Mr Bennett was issued.
Mr Farira told the BBC the warrant was immediately seized by a senior prison official, who then disappeared with it.
It is not immediately clear when Mr Chipadze will be taken to court.
Mr Bennett was granted bail by the High Court last week but the Attorney General office immediately appealed against the ruling.
The Supreme Court on Wednesday allowed the appeal to proceed and ruled that Mr Bennett would remain in custody until the case was heard.
Mr Bennett is a white farmer, whose land has been seized under Mr Mugabe's land reform programme. Some of his employees were killed and assaulted during the violence.
An MP since 2000, he was jailed in 2004 after pushing a minister in parliament during a heated debate about land reform.
After being accused of links to the alleged plot to kill Mr Mugabe in 2006, he fled to South Africa, saying he feared for his life.
Long-time rivals President Robert Mugabe and MDC leader Morgan Tsvangirai last month formed a unity government after months of wrangling.
They pledged to make reviving the economy a top priority, but analysts say Mr Bennett's arrest is causing serious difficulties for the fledgling administration.