Earlier this week, Zimbabwe confiscated the passports of two government critics including newspaper owner Trevor Ncube, but later returned them.

The constitution was amended to allow for passport confiscations, but there has been no enabling legislation yet.

Mr Ncube meanwhile has published a list of 17 people whose passports the government has cancelled.

Opposition official Paul Themba Nyathi and Mr Ncube got their passports back after starting the legal action against the government.

"It is declared that the purported invalidation or withdrawal or cancellation of the applicant's passport is unlawful, null, void and of no force and effect," High Court Judge Chinembiri Bhunu said, Reuters reports.

In August, the constitution was amended, authorising the government to seize passports of those not acting in the national interest, but no framework to allow this to happen have yet been passed.

Trade unionist Raymond Majongwe has also had his passport seized on Wednesday.

He is secretary general of the Progressive Teachers' Union of Zimbabwe and airport officials took his passport as he returned from a trip to Nigeria.

Invalidated

According to the list published by Mr Ncube's South African Mail & Guardian newspaper on Thursday, Catholic Archbishop Pius Ncube, and Movement for Democratic Change leader Morgan Tsvangirai are among those whose passports have been invalidated by the Zimbabwe government.

Human rights lawyer Beatrice Mtetwa, MDC secretary general Welshman Ncube, and prominent businessman Strive Masiyiwa are also on the list.

Mr Masiyiwa took the government to court to get a licence to set up a mobile phone network. He is now based in South Africa.

Mr Themba Nyathi and Trevor Ncube were both told by officials last week they were on a list of 64 people whose passports the government intended to seize.

On Wednesday both men were told they could collect their passports from the department of immigration in Harare, before their legal action against the government had gone to court.

But Mr Themba Nyathi said he felt it would just be a matter of time before his documents were seized once more.