Roy Bennett, a nominee for deputy minister of agriculture, was arrested at a Harare airport and charged with treason for allegedly plotting to kill Robert Mugabe, the Zimbabwean president.
The Movement for Democratic Change (MDC) party's statement described the charges against him as "scandalous" and "politically motivated".
Al Jazeera's Rory Challands reports.
The World Cup football tournament kicks off in one week, and host South Africa is busy putting on the finishing touches. But not everyone is looking forward to the tournament. Authorites in cities including Cape Town are being accused of clearing the poor from the streets - to create a good impression for visiting fans. Al Jazeera's Haru Mutasa has more.