Detective Senior Sergeant Richard Corbidge, of the Auckland police child protection team, told the Herald on Sunday that the investigation was ongoing and officers were working closely with Child, Youth and Family.
"It's a very sensitive and protracted inquiry," he said. "Further charges were laid (on Friday) and I would anticipate there would be further charges in the future."
Anyone with concerns is being encouraged to call the police.
Corbidge said: "We have a number of complainants and that could rise. As a result of the publication of Mr Todd's name, if anyone would like to contact police in relation to that, they can do so on 09-302-6400."
Two of the 20 charges against Todd involve arranging to meet, or persuading to meet, a young person for sexual grooming. Police say the other 18 are allegations of indecency towards children and young people.
On Friday, Judge Jonathan Down remanded Todd in custody to reappear in two weeks.
Members of Todd's family were in the court for his appearance.
Defence lawyer Guyon Foley said outside court that Todd was now a full-time student and no longer worked at the organisation at the centre of the allegations.
He said Todd's departure from the organisation was unrelated to the case.