Baber said police received a large volume of phone calls and emails from former Dilworth students of the school.
But he still encouraged anyone with information to contact Operation Beverly by phoning (09) 302 6624 or emailing Operation.Beverly@Police.govt.nz.
Dilworth School was opened in 1906 with the aim of helping boys from disadvantaged families.
But police allege serious offences occurred at the school from the 1970s to the 2000s.
Although news of the arrests broke in September, Operation Beverly started in mid-2019.
Baber said the additional charges announced today were all against five men who were already before the courts as a result of the investigation.
Alister Grant Harlow and Ian Robert Wilson were named on October 5 in relation to the alleged offending.
Harlow, a Hillsborough accountant aged 60, faced a charge of indecently assaulting a boy aged over 16 in 1990.
He was associate housemaster of Erin House at the time of the alleged offending.
Harlow has a district court trial date set for February 2022.
In October, Scouts chief executive Joshua Tabor told the Herald police had been in contact about the Dilworth allegations and the organisation was "co-operating with the investigation".
Tabor confirmed that Harlow and Wilson contributed to running the Scout group at Dilworth.
Wilson, of Maraetai, pleaded guilty to two charges involving indecent acts while he worked at Dilworth School.
Wilson started at Dilworth in 1971 and became Assistant Principal after holding many senior roles at the school.
Rex Clarence McIntosh, who lost name suppression in November but could not be named until December 9, has denied charges of indecent assault relating to two complainants.
Manurewa vicar Ross Douglas Browne, an Anglican priest and former Dilworth chaplain, also faces charges.
Browne, 72, was also heavily involved in Scouts and amateur theatrical company the Auckland Gang Show.
The Herald in October reported Browne was accused of indecently assaulting three boys between 1991 and 2002.
One of the men charged died on November 26.
He still had name suppression.
He had been earlier diagnosed with cancer.
The man was accused of indecently assaulted a boy between the start of 1975 and the end of 1976.
Where to get help:
• If it's an emergency and you feel that you or someone else is at risk, call 111.
• If you've ever experienced sexual assault or abuse and need to talk to someone call the confidential crisis helpline
Safe to Talk
on: 0800 044 334 or text 4334.
• Alternatively contact your local police station
• If you have been abused, remember it's not your fault.
