There must be information police have held back in the inquiry into 44 deaths during labour unrest at Marikana last year, the Farlam commission said on Thursday.
Spokesperson Tshepo Mahlangu said this had been discovered in the past 10 days.
The commission has, therefore, postponed its proceedings until Wednesday next week.
"In the past 10 days we have discovered through the evidence leaders that there must be info that was not disclosed by the police that seeks to suggest that the information was withheld to try and portray a certain approach to the commission in relation to what has been discovered," said Mahlangu.
The commission said, "First, we have obtained documents which the SAPS [South African Police Service] previously said were not in existence. Second, we have obtained documents which in our opinion ought to have been previously disclosed by the SAPS, but were not so disclosed.
"Third, we have obtained documents which give the impression that they are contemporaneous documents, but which appear in fact to have been constructed after the events to which they refer – in some instances at the time of the nine-day Potchefstroom meeting at which members of the SAPS prepared the case which they were to present to this commission.
"Fourth, we have obtained documents which in our opinion demonstrate that the SAPS version of the events at Marikana, as described in the SAPS presentation to this commission and in the evidence of SAPS witnesses at this commission, is in material respects not the truth."
Previously, evidence leader Geoff Budlender SC asked that the commission be postponed to allow his team to examine the police evidence.
In Lieutenant Colonel Duncan Scott's version on a computer hard drive containing the police's evidence, "some documents have been added and some files we haven't seen before", Budlender told the commission.
He said the police team had been co-operative, but that the process of going through the evidence "could take some time".
The commission, sitting in Centurion, is investigating the deaths of 44 people during strike-related unrest at Lonmin's platinum mining operations at Marikana, near Rustenburg in the North West last year. Police shot dead 34 people, almost all of them striking mineworkers, while trying to disperse and disarm them on August 16 2012.
Ten people, including two police officers and two security guards, were killed in the preceding week.
President Jacob Zuma established the commission shortly after the unrest. – Sapa