A top official in the party of Zimbabwe's prime minister was arrested Friday, sparking fresh fears the impoverished African nation's power-sharing agreement may collapse.

Roy Bennett, a white farmer and the opposition Movement for Democratic Change's candidate for deputy agriculture minister, was reportedly seized at a Harare airport ahead of a ceremony to swear in a coalition cabinet.

No reason was given for Bennett's arrest, said officials from the MDC, whose leader Morgan Tsvangirai was sworn in as prime minister by President Robert Mugabe earlier this week.

Bennett, first elected to Zimbabwe's Parliament in 2000, lost his coffee farm under the land seizure programs implemented by Mugabe's ZANU-PF party.

He recently spent more than two years in exile in South Africa after being listed along with several other MDC officials in an alleged plot against the president. The criminal complaint against the other officials was later dropped.

In 2005, Bennett served eight months in prison, a punishment imposed by the ZANU-PF dominated Parliament for shoving the country's justice minister during a parliamentary debate. He has also said he received death threats.

Dispute delays swearing-in ceremony

Friday's inauguration ceremony was delayed over a last-minute dispute that underlined the challenges of bringing the MDC into government with a party that has beaten and detained opponents.

Mugabe arrived for the ceremony with plans to swear-in seven ZANU-PF members as junior ministers; the opposition said they were to be sworn in next week.

The ceremony later went ahead, though it was not immediately clear how the dispute over the junior ministers was resolved.

Under pressure from other African nations, the two rivals finally agreed to form a power-sharing government and work together for the good of the country in the wake of its complete economic meltdown.

Under the power-sharing agreement, Mugabe and Tsvangirai are to jointly oversee a Cabinet of 31 — 15 from Mugabe's party, 13 from Tsvangirai's and three from a breakaway opposition faction led by Arthur Mutambara.

90 per cent unemployment

A former trade union leader, Tsvangirai won the most votes in the first round of the presidential election last March, but pulled out of the runoff with Mugabe because of violence against his supporters.

Zimbabwe's unemployment rate hovers around 90 per cent and the inflation rate is estimated to be more than 230 million per cent. Roughly half of the country's population — 6 million people — need food aid.

With prices for food and other goods almost doubling daily, the Zimbabwean dollar is virtually worthless. There is speculation the country could adopt the South African rand as its official currency.

A countrywide cholera outbreak has killed more than 3,400 people since August, while basic water and sanitation infrastructures are crumbling.

Mugabe, 84, has ruled Zimbabwe since it won independence from Britain in 1980.

With files from the Associated Press