Despite a falling out, Zimbabwe's opposition leaders joined forces
A senior Zimbabwean opposition politician has been arrested over a written attack on Robert Mugabe.
Arthur Mutambara, who recently pledged to work with a rival opposition leader to defeat President Mugabe in run-off elections, was detained in Harare.
His lawyer told the BBC his client had been accused of publishing falsehoods and contempt of court after a critical article he wrote in April.
Mr Mutambara leads a break-away faction of the country's main opposition group.
He was arrested at his home and his lawyer believes he is being held at a Harare police station, the BBC's Caroline Hawley reports from Johannesburg.
Our correspondent says Mr Mutambara is the most senior opposition figure to be arrested thus far in a state-run campaign of political intimidation.
The editor of the country's only independent Sunday paper, The Standard, was arrested last month over Mr Mutambara's article, which accused Mr Mugabe of running down the Zimbabwean economy and his security forces of abuses.
Mr Mutambara fell out with main Movement for Democratic Change (MDC) leader Morgan Tsvangirai in 2005, but had recently agreed to work with the MDC in the lead up to 27 June run-off election between Mr Tsvangirai and Mr Mugabe.
Mr Mutambara's lawyer said he did not expect his client, who lost his parliamentary seat in the 29 March general election, to be brought before a court until Tuesday.