Blenheim Gymnastics Club says it is shocked to learn of serious sexual offending against by one of its former coaches.
On Monday, Gregory Pask pleaded guilty at Blenheim District Court to 29 charges of sexual offending against several girls and producing objectionable material between 2014 and September this year.
Marlborough CIB Detective Sergeant Ash Clarke said police believed there could be further victims.
The club issued a statement on its website, saying it was appalled to learn of offending by Pask, who had a position of trust in the community.
It was aware of the legal proceedings, but had been unable to comment due to suppression orders which prevented details being made public before Pask entered guilty pleas on Monday.
The club said its primary concern was the well-being of the victims and had reassured members that it was a safe place.
Gymnastics New Zealand chief executive Andrea Nelson said the organisation was also ensuring the victims of Pask's sexual offending were receiving the support they needed.
The offending was a "horrible reminder" that all sport and recreational activities where children were supervised by adults were vulnerable to child safeguarding issues, Nelson said.
"It can happen anywhere - and all people who work or volunteer in the sector need to be vigilant and alert to these threats."
The organisation was closely monitoring the situation, with the wellbeing of the victims its main concern, Nelson said.
It would continue to monitor developments in the case and take any actions required to support the safety and wellbeing of its participants and members.