The principal of an exclusive Brisbane boys primary school says revelations about a staff member been charged with sexual abuse is ‘a real shock’.

The principal of an exclusive all-boys primary school in Brisbane has spoken of his devastation after a staff member was charged with the indecent treatment of children.

The Nudgee Junior College staff member in his late 40s is in police custody, charged with four offences allegedly committed this year.

Principal Michael Senior wrote to parents on Monday to say the school wasn’t aware of the allegations until police informed them on Friday.

Mr Senior later told reporters the school was shocked but declined to take questions.

“We’re obviously devastated with the events of the last 24 hours,” he said outside the front gates.

“This has come as a real shock to us in coming to terms with that.”

He said the detectives asked for, and immediately received, full co-operation from the Catholic school, in the inner Brisbane suburb of Indooroopilly.

In a letter to parents, obtained by AAP, he wrote: “The staff member will be stood down immediately.”

“The college is devastated by this matter and is doing everything possible to support the alleged victims and their families.”

Mr Senior informed each year level separately on Monday and additional counselling is being offered.

“Today I talked to them about the need for them just to understand the situation. But more particularly, for them to be aware of our child protection policy where it’s our hope that all the boys can feel safe at our school and if they don’t feel safe, the steps that they can take to ensure that they do feel safe,” he told reporters.