"I thought we were just going down there to train some Maori youths to get a better life,'' the elder brother told the court. He was 16 at the time.
He said Iti gave them cloths and told them to put them over their face to protect their identities and to cover their eyes with blindfolds.
The group then drove into the bush with Iti at the wheel.
"We were stopped at a set-up road block. There was a log across the road and a man holding a gun and a stick... He fired some shots into the air and asked us to get out of the car.''
The man said about 10 or 11 people were around the car and he saw that four of them had guns.
"They told us to lie on the ground facedown while they patted us down.''
He was asked by Crown prosecutor Ross Burns how he felt about that.
"I didn't really think that much,'' the man told the court, "I was just in shock.''
He said afterwards they walked up a bush track to a make-shift camp site where there was a discussion about nutrition.
"We did some demonstrations like kicking and punching and stuff.''
He said that on the way back to Ruatoki there was a discussion in the car.
"Mr Iti claimed it was [for] training troops for battle, urban warfare and stuff like that.''
Under cross-examination from Iti's lawyer, Russell Fairbrother, the man confirmed that Iti did not wear a mask and was also ordered out of the car and patted down.
He told Mr Fairbrother that the group had apologised for the ambush.
The trial continues.