In a letter sent to parents and carers on Friday afternoon, All Saints' acting principal Nathan Mansfield confirmed the 39-year-old male teacher who has been charged by NSW Police is "no longer employed by the Catholic Diocese of Maitland-Newcastle".

"The alleged actions of this individual clearly violated our Diocesan Code of Conduct, and NSW Police's quick progression to press charges indicate the seriousness of these accusations," he said.

"This individual no longer holds accreditation to teach on a search of the NSW Education Standards Authority (NESA) public register.

"The Diocese of Maitland-Newcastle places the safeguarding of children and vulnerable people first.

"All allegations of abuse are responded to and taken seriously."

The 39-year-old was arrested on March 28 at Maitland Police Station, following an investigation by Port Stephens-Hunter Police District officers.

He has been charged with nine counts of sexual intercourse with a person under care, between the age of 17 and 18, has since been granted conditional bail and will face Maitland Local Court at the end of the month.

In his letter to families, Mr Mansfield reminded staff of the legal obligations for all teachers, including school principals and leaders, to report matters concerning actual or possible risk of harm to a child.

"We appreciate the responsibility to continue to keep the school community informed, however, this must always be balanced against ensuring the integrity of the investigations being undertaken and protecting the privacy of all other parties."

School leadership were made aware of the allegations against the 39-year-old on the afternoon of Wednesday, March 13 and reported it to the relevant statutory authority the same day.

He was placed on administrative leave on March 14, the day after the allegations were made, and that administrative leave ended on Friday.

A second individual facing a "connected but very separate" allegation remains on administrative leave while investigations continue.

Mr Mansfield said that dependent on the findings of that investigation, "appropriate action will be taken".

"The Diocese of Maitland-Newcastle has a zero tolerance for abuse and takes safeguarding seriously, placing the safeguarding of children and vulnerable persons first," he said.

"As is always the case with our Diocesan system of schools, we encourage you to contact the leadership of the school with any concerns you may have."

The Office of the Children's Guardian (OCG), the state's independent authority which oversees organisations to ensure the safety of children, confirmed in March it had been notified about the alleged incidents.

An OCG spokeswoman said at the time it had been contacted by the diocese about allegations that saw two teachers put on administrative leave.

"The Diocese of Maitland-Newcastle has been in contact with the OCG about the matters referred to in its public statement and we can confirm that it has made the required reports," she said.

"We cannot disclose any further information about these matters at this time."

Support has been made available to members of the school community through the Diocesan Employee Assistance Program at 1800 613 155.

They may also contact the Diocese's specialist child protection service, the Office of Safeguarding, at 4979 1390 or its confidential Whistleblower Hotline run by PKF Australia on 1300 989 183.