Patrick Foley Wilson was charged by NSW police on June 9 after officers assumed the online identity of a 13-year-old girl and spoke with him online.

He was arrested in Parramatta and police allege he made a number of sexually explicit comments and talked of meeting the child.

Wilson had worked at the Canberra Boys Grammar School since the start of 2015, but the charges do not relate to his employment or students at the school.

In a statement released a day after the arrest, Canberra Boys Grammar School head of school Dr Justin Garrick said the Deakin man was stood down immediately and without pay.

But on Thursday, six weeks after Wilson was arrested, the principal of Canberra Girls Grammar School Anne Coutts told parents the man had also taught at the school for two terms.

"He had a valid ACT Working with Vulnerable People and was registered with the ACT Teacher Quality Institute," she said in a letter to parents and guardians.

"However, we have no indications at this time that any Canberra Girls Grammar School students are involved."

Ms Coutts said the school had no additional information about the man's alleged misconduct other than a police media statement.

"Canberra Girls Grammar School was not permitted to engage in any pre-court name disclosure and legal advice received was to allow the court process to unfold," she said.

"With respect for integrity of the court process having to unfold there are no more details available at this stage."

Ms Coutts said the school would cooperate with authorities should there be any need to do so.

"Once again, on behalf of Canberra Girls Grammar School we reaffirm our determination that the prime focus has been and always will remain the welfare and safety of our students," she said.

On June 10, Ms Coutts wrote to parents to assure them Wilson was not a current teacher at the school but did not detail his previous employment with the school.

"I would ask parents to immediately contact the school if there are concerns about this matter," she said in the letter.

"We also remind parents and students to be vigilant around internet use or activity and to discuss internet usage."

In his statement, Dr Garrick told the school community he was relieved by police assurances the alleged offences did not relate to the school but appreciated "how disturbing this news will be to our community".

"I felt it important to inform you as soon as possible after receiving confirmation and clearance from the police," he said.

Wilson appeared in the Parramatta Local Court on Wednesday, his first appearance since being charged and bailed by police.

No pleas were entered and the matter was adjourned until October.