Trinity Grammar teacher charged with online child grooming

A teacher at an elite Sydney boys' school is under investigation for alleged online child grooming.

Alex Simpson was arrested on the grounds of Trinity Grammar in Summer Hill, in Sydney's inner-west yesterday and his home in Padstow Heights was raided.

The 39-year-old English teacher is accused of sending sexually explicit messages to a person he allegedly believed to be a 13-year-old girl but was actually an undercover police officer.

It will also be alleged the father was taking part in sexually explicit conversations while at work.

"A person in a position of trust such as a teacher and engaging in this type of activity is certainly of a significant nature and they are very serious charges," Detective Acting Superintendent Chris Goddard said today.

Mr Simpson faced Burwood Local Court today and did not apply for bail.

Trinity Grammar said it is cooperating with NSW Police and the teacher has been stood down.

"The police have informed the School that there is no suggestion that offences have been committed against Trinity students," the school said in a statement.

"The member of staff has been stood down; the School continues to provide pastoral support to staff and students."