Charges of treason against Roy Bennett, a senior official of Zimbabwe's Movement for Democratic Change (MDC), have been dropped and replaced with sabotage.

The move on Sunday came two days after Bennett, a white farmer and cabinet nominee, was taken into custody in the city of Mutare.

Trust Maanda, Bennett's lawyer, told Al Jazeera that the treason case did not "hold water".

Maanda said police now claim sabotage in relation to Bennett allegedly plotting to buy arms to attack a telecommunications station in Bromley, east of Harare, the Zimbabwean capital.

Bennett, who denies the charges, remains in custody and will appear in court on Monday.

Bennett's arrest came hours after a unity government, comprising the MDC and President Robert Mugabe's Zanu-PF party, was sworn in.

Bennett and other deputy ministers are still waiting to be officially appointed.

The MDC had called the first charges "scandalous, vexatious and without basis in law" and "politically motivated".

Unity government doubts

Bennett had been living in exile in South Africa for two years after fleeing the country to escape charges of plotting to kill Mugabe, but returned last month.

He became treasurer of the MDC and was nominated by Morgan Tsvangirai, the MDC leader and now prime minister of Zimbabwe, for the post of deputy minister of agriculture.

Doubts have now been raised over the stability of the new unity government, which took several months to agree upon.

However, the MDC has not indicated yet if the arrest will trigger a crisis and endanger the coalition.

Foreign investors and western donors have said that funds will not reach Zimbabwe - which is undergoing an economic and humanitarian crisis - if there is no stability in the country.

Disputed elections prompted political violence in Zimbabwe in March.

Mugabe then won an uncontested presidential run-off in June, and a power-sharing deal was signed three months later.

However, disputes concerning the distribution of cabinet positions between the MDC and Zanu-PF prevented a unity government from being formed until last Friday.