The National Party has banned a member of its youth wing from attending any party or Young Nationals functions pending the outcome of a police investigation into claims of inappropriate behaviour.
In a statement, the party said it became aware of the names of the alleged victim and alleged offender only yesterday morning.
"This information had not been communicated to us previously at the direction of those involved."
The party then wrote to the man outlining the issue, its concerns, and gave him a chance to respond.
"Given the nature of the allegations and our responsibility to ensure the safety of our members, we consider it fair and appropriate that the alleged offender not attend any National Party or Young National functions, pending the outcome of the police investigation," a party spokesman said in a statement.