"The evidence presented raises serious questions about the truthfulness of what the police told the commission," said Bruce.

"If this is the case and the evidence presented has been done with the agreement of police management, then this raises questions about the involvement of senior officers in the cover-up," he said.

Yesterday, lawyers representing the Marikana miners who were wounded in the August 16 shootings and the families of the 34 miners killed presented photographs and video footage suggesting thatpolice might have planted weapons on slain miners and that some of miners who were killed had their hands tied behind their back at the time.

Bruce said South Africans had good cause to be concerned.

"A situation is developing where police witnesses see nothing and know nothing to avoid answering questions. It is a good way of avoiding being caught out lying to the commission.

"It is becoming more and more obvious that the police and the evidence they are presenting is of dubious credibility," he said.

Bruce questioned why a police "debriefing" after the shooting should take nine days.

"One does not need a nine-day meeting to present truthful evidence. If one presents truthful evidence one would make witnesses immediately available - which did not happen," he said.

Bruce said what was worrying was how far up the complicity appeared to go.

"If the national commissioner authorised the use of maximum force then she effectively gave an illegal instruction. We are talking about the use of an entire police force as a political instrument for certain factions," he said.

"Heads need to roll - those of the commissioner, the minister, not just for this massacre, but for so many other criminal matters, [from the] failure to stop crime to irregular spending."

Bruce said those in power should be held to account.

"If this had been any other democracy, resignations would have occurred immediately," he said.

Police Department spokesman Zweli Mnisi said they would not comment on evidence being led at the inquiry.

"The matter is sub judice. Analysts are there to analyse," he said, referring to Bruce's comments.