"Both organisations are aware of the allegations and are cooperating fully with our investigations."
The investigation team would like to hear from anyone who may have been subject to inappropriate advances over this time period or whose children may have exhibited behaviours of concern, Mr Greene said.
Police were also working with both youth organisations to help them improve processes around vetting of personnel and early identification of potential victims to prevent similar incidents from occurring, he said.
"Incidents such as this are very disappointing when reflecting on the good these organisations do for our communities and youth, and the impact such revelations may have," Mr Greene said.
"The most important thing remains however, for us to identify any other potential victims and get them the support and care that they may need."