He told the court he had watched hours of covert footage and if it was all added up it would probably amount to days, if not weeks.
"Now we have Mr Hunt demonstrating what appears to be a shooting stance," he said, referring to the footage being played on a screen in court.
A short time later Tame Iti walks through the camera shot "observing the group" while Mr Hunt talks to the masked people with guns, the court heard.
The alleged exercise showed one man with a rifle crouching behind a four-wheel-drive while sighting a rifle. A short time later two other figures run from the vehicle with guns in their hands.
The group then appear to have a conversation.
Mr Lunjevich said they also received hand-to-hand combat lessons from Mr Hunt who, at one point, put one of the members in a wrist lock.
In his opening address to the trial last week, Crown prosecutor Ross Burns quoted from an online conversation between Tame Iti and another man in which they identified Mr Hunt as "a new trainer from Baghdad".
He said the exercise was training for getting out of a vehicle under fire.
The jurors were also played recordings of loud bangs which the Crown says are gunshots fired on the day of the camp.
Under cross-examination from Iti's lawyer, Russell Fairbrother, Mr Lunjevich was asked how he could be sure the gunshots came from the group of people on the video.
"All I know is it came from that timeframe," Mr Lunjevich said.
The officer was also asked how he could be sure the firearms in the videos were not "$2 shop imitations".
Mr Lunjevich said the guns on the video were consistent with those found after police raided properties.
"I got to see a number of the firearms and they bare a striking resemblance."
The trial continues.