The Movement for Democratic Change's chief elections officer, Morgan Komichi, faces prosecution for producing a stray ballot paper cast in his party's favour during the special vote earlier this month.
Komichi took the ballot paper - which the MDC said was found in a rubbish bin and given to the party by an anonymous supporter - to the Zimbabwe Electoral Commission, saying that it was proof that there had been fraud during the voting by army and police personnel.
He was arrested on Sunday. Yesterday police said they would hold Komichi until he revealed from whom he had received the ballot.
The MDC has repeatedly raised concerns about the possibility of electoral fraud.
In a column written by Tsvangirai and published in the Washington Post yesterday, the MDC leader said: ''Mugabe is attempting to steal Zimbabwe's most important election."
On Sunday, Mugabe warned Tsvangirai that he would be arrested if he violated Zimbabwe's electoral laws. He was referring to a threat by Tsvangirai to announce the election results himself if they were delayed to pre-empt rigging.
The hugely popular but anonymous Facebook character Baba Jukwa said yesterday that he would announce results .
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