Peta: Commonwealth must act against Mugabe
Speaking on the BBC's Today programme, Mr Peta said that other countries should continue to put pressure on President Robert Mugabe to force him to adopt more democratic methods.
"It's very important that the international community be seen to do be doing something to rein in Mr Mugabe in Zimbabwe," he said.
"What must now follow is the further threat of broader sanctions against his regime if he doesn't change his ways."
Further action
He also said that it was now "incumbent" for the Commonwealth to act in turn against Mr Mugabe despite its current reluctance to impose further sanctions.
"If it [the Commonwealth] is going to be divided and remain inactive against Mr Mugabe then I think it's the Commonwealth that is at risk," he said.
Mr Peta, a reporter for Zimbabwe's Financial Gazette newspaper and a local correspondent for the British Independent newspaper, fled from Zimbabwe on 14 February this year after attacks on him by state-controlled media.
Fair elections
In a later interview, he also warned that an election victory for the opposition Movement for Democratic Change (MDC) and its leader Morgan Tsvangirai was far from assured, due to restrictions on the media and abuse of state resources by the ruling party, Zanu-PF.
"They [the opposition] have not been able to penetrate the entire country, campaign and get their message across," he said.
"The playing field is tilted in favour of the ruling party."
As the EU observers prepare to leave Zimbabwe, Mr Peta said he felt it was unlikely their presence would have been enough to maintain an impartial election.
"I don't see how the observers were going to operate," he said.
"Mr Schori [the expelled head of the EU observer mission] has made it clear that a number of unacceptable conditions had been imposed on them."