In the wake of the alleged incident, a complaint was made to the Judicial Conduct Commissioner who then informed the Chief District Court Judge.
A spokeswoman for the Office of the Chief District Court judge said in a statement: "The Chief Judge is aware of a recent complaint made to the Judicial Conduct Commissioner.
"The integrity of the Commissioner 's process for dealing with complaints must be respected, therefore it is inappropriate to comment on or interfere in any way in that independent process. That independence is its strength.
"The judge in question has been on sick leave since the complaint came to the attention of the Chief Judge. The Chief Judge will be making no further comment."
It is understood the young lawyer did not make the complaint.
Angus Fletcher, who is a trustee, said he did not personally witness the alleged incident. "I'm not denying I'm aware that something happened," he said. "Information is made available to me as a trustee."
Judge Johns was appointed to the court in 2005, having practised as a barrister since 1998. She had previously sat as a member of the Refugee Status Appeal Authority and worked at Meredith Connell as a senior trial prosecutor and for the Serious Fraud Office.
The fundraising event was to support the Rangimarie Trust, which was set up two years ago to enable Michelle Kidd to continue her work with the homeless and vulnerable at the Auckland District Court. Ms Kidd has worked for almost two decades with defendants, victims and families of both to be prepared for court hearings and the pressures around hearings.