"There's a formula for use by the search and rescue experts for waterborne searches and recoveries and so adhering to that, we obviously did the intensive search Friday, Saturday and Sunday using divers and a number of boats,'' the spokesman said.
"Now, applying the formula, there are set dates or time periods that they believe are the most optimum time to recover a body.''
Wednesday's search would cover areas already searched; the Waikato River downstream from the bridge, including the immediate area and around the Huntly Power Station.
Zharian's brother, Tyrone, said he had been warned against jumping from the bridge but Zharian's friend, Zaden Callaghan, said students from Huntly College would jump off the bridge after school.
"But it depends what the water's like, because sometimes it's shallow, sometimes it's deep. You don't really know and the current can be kind of fast on some days,'' he told National Radio.
Zaden said Zharian's family was devastated. The teenager was one of three brothers and his mother was pregnant with a fourth child.