An investigation has been launched after parents of children at a grammar school were warned their personal details may have been hacked.

Southend High School for Boys’ WisePay system suffered a cyber-attack this month and confidential payment card details may have been exposed.

WisePay is a school income management system dealing with things such as bookings for trips and clubs and paying for lunches.

In a letter to parents, WisePay said: “ At some point around October 2, we understand that a cyberattack occurred in the form of a URL manipulation, meaning that the payment gateway page was redirected or controlled by a bad actor, and your payment card data may have been unlawfully disclosed.

“Wisepay has provided the school with a list of those who have, potentially, been affected. WisePay has engaged a computer forensics expert and the forensic investigation is ongoing. We recommend that you are especially cautious regarding your personal financial arrangements and take prompt steps to pause or cancel the payment card you used on our site.”

Parents have been urged to change current passwords and login details for bank and credit cards and warned to be vigilant about any unusual activity regarding their accounts.

The company added: “WisePay took its website offline until the incident was remediated. It is also taking steps to implement additional security measures designed to prevent a recurrence of such an event.

“WisePay also has notified the UK’s Information Commissioner and law enforcement to ensure the incident is properly addressed.”

Dr Robin Bevan, headteacher at Southend High School for Boys said: “We know that WisPay services a very large number of schools all across the country and they did a superb job of letting us know at the earlies opportunity.

“We were able to contact parents and were able to contact those whose details had been compromised. Children still to continue to use WisePay to by lunches.

“We’ve been able to support and offer guidance where needed. A very small number of parents were concerned and we are not aware of any parent who has lost money. WisePay continues to be a trusted partner and has provided and excellent service for many years.”