The judge in Jackie Selebi's corruption trial will decide on Thursday whether he will need to hold a trial within a trial over the admissibility of a video as evidence.

The defence wants the judge to see the tape which it believes is crucial to its case.

In the meantime, Selebi's advocate is continuing with cross-examination of the state's key witness Glen Agliotti.

The tape, recorded in January last year, shows Agliotti apparently making contradictory statements about bribing Selebi.

In the meantime, advocate Jaap Cilliers wants to know why Agliotti never attempted to set up Selebi by arranging a controlled handover of cash or by recording conversations with the accused.

Tensions are high as the two are continuously bickering.

At one point Judge Meyer Joffee slammed his hand on his bench to calm tempers.