A top-secret document allegedly implicating Zimbabwe's security chiefs in illegal diamond dealing has come under the spotlight in a court case in Harare.

Farai Maguwu, a witness to alleged irregularities in the country's diamond trade, was yesterday charged with "publishing and communicating false statements prejudicial to the state".

The trial continues today.

Maguwu was arrested days after he gave Kimberley Process monitor Abbey Chikane a document now considered to be "top secret". The document was said to have been fraudulently obtained from the Zimbabwe Republic Police.

There was drama after Magawu handed Chikane the document as part of his evidence alleging that the illicit diamond trade at Chiadzwa, in the east of the country, was still going on.

Magawu, director of the Centre for Research and Development, said Zimbabwe had not made progress in meeting expected diamond-trading norms.

Security agents swooped on his house in Mutare City, but Magawu escaped. After spending days in hiding Magawu gave himself up to police last Thursday. He was detained and taken to Harare.

Chikane was in the country to assess compliance with the Kimberley Process Scheme. This week he gave Zimbabwe the thumbs up, but the contents of the document could undo his efforts to allow the country to trade in diamonds.

The international campaign group Global Witness yesterday queried the credibility of the Kimberley Process report, which said Zimbabwe had met standards to resume trade in the gems.

"There is no sign that state-sponsored brutality in diamond fields has stopped or that widespread smuggling has been curbed," Global Witness said. - Additional reporting by Sapa-AFP