In a release, the Metropolitan Police confirmed the arrest of the 40-year-old woman on Wednesday, and said it related to a Tuesday incident at the school “when an individual gained access to its premises.”
“The woman was arrested in the vicinity of the school and has been taken to a south London police station where she remains in custody,” said the police.
“We are working with the school, which is attended by His Royal Highness Prince George, to review its security arrangements after the incident.”
Kensington Palace tells PEOPLE, “We are aware of the issue but we would not comment on security matters.”
Prince George was at school Tuesday and Wednesday. It’s understood that at the time of the arrest, the children from the class that George is in, had left for the day.
Prince William and Princess Kate have vowed to take George to school or pick him up “as often as they possibly can,” a royal source says.
The release also noted that while police are part of the security arrangements for Prince George, Thomas’s Battersea is responsible for its own on-site security.
According to The Telegraph, the incident was not the first time security at the school has come into question. A local resident, 54-year-old Sarah Burnett-Moore, said she was able to walk right into the school because a gate and main door were left open – just days before Prince George’s school year began.
The prince, 4, had his first day of school at Thomas’s Battersea on Sept. 7. His father accompanied him on the special occasion.
Ben Thomas, former headmaster of Thomas’s Battersea and now the principal across several sister schools, previously told reporters that George will be treated the same as every other student at the school, and hopes that he’ll feel “supported” in the school’s environment.
“Our aim for him, as well as for all of our pupils, is to provide a safe and secure and happy environment where he feels supported by a kind and loving community,” Thomas said. “That’s something we will be trying to achieve for him.”
This article originally appeared on PEOPLE.