"I cannot exclude the possibility that some of the 600 officers who were there could have other [pictures and videos on their cellphones] that they did not hand in," Major General Charl Annandale told the commission, which is sitting at the Rustenburg Civic Centre.
Annandale headed the police tactical response team during the unrest.
Under cross-examination, Annandale said the officers were asked to hand in any information they had, but that there had not been any requirement for them to use their cellphones in the first place.
Deaths at Marikana
The commission is investigating the circumstances surrounding the deaths of 44 people - 34 of them shot dead by the police - during unrest near Lonmin's platinum mine in Marikana in August.
"There's no protocol for officers to use their own private cellphones and cameras, as professional people are appointed for such," Annandale said.
Five police videographers were deployed to take footage during the unrest.
Some cellphone footage has also been entered into evidence.
Earlier in proceedings, Nokukhanya Jele, for the SA Human Rights Commission (SAHRC), said it waited several months to acquire the pocket-books of police officers deployed at Marikana.
After a short adjournment, Jele told the commission it had just received around 500 of these books from the police.
The commission heard that the pocket-books could contain crucial information.
A typical entry in officers' pocket books would have information on the posts they held on a particular day, the type of vehicles they used, and the type of firearms they had in their possession, Annandale said.
"In terms of Marikana, they would say when they went on duty and whether they used their firearms or not," he said.