State witness Glenn Agliotti is undergoing intense cross-examination by Jackie Selebi's advocate about contradictory statements he made about bribing the former police chief.

Selebi's advocate accused Agliotti of lying in the witness box.

The ex-police chief is facing charges of corruption and defeating the ends of justice.

With his credibility on the line, Agliotti tried to explain why he made contradictory statements about bribing Selebi in two affidavits he made in January last year.

Agliotti said his understanding of the legal definition of bribery changed after his advocate explained corruption did not necessarily mean a quid pro quo relationship.

Sparks flew as Selebi's advocate Jaap Cilliers accused Agliotti of lying to the judge and accused him of concocting a false explanation.

Cilliers warned the witness to listen carefully to his questions because an innocent man's life was on the line.

Agliotti was cocky in response, challenging every accusation.

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