Newcastle United have cancelled more than 100 season tickets and apologised to supporters for an "oversight" after seats sold to tour organisers a decade ago were "not detected until recently".

The club have taken action following a further investigation into the unauthorised re-selling of tickets for matches at St James' Park.

It comes in the wake of a school nearly 200 miles away being able to buy tickets for the massively in-demand Champions League home game against Barcelona on Thursday night.

The club explained that when the new owners took over four years ago, they ended agreements with third parties that allowed them to sell tickets.

That included the deal agreed a decade ago with a small group of tour organisers "for the benefit of school groups" - but the club did not realise they were still selling tickets because there was no formal deal with the organisers.

"At a time when we are doing our utmost to protect legitimate access for Newcastle United fans, we want to be fully transparent and apologise for this oversight," the club said.

Forty-five tickets for the Barcelona match were bought by the High School of Dundee in the same month that 110,000 fans had been in an online queue for the remaining seats for the highly anticipated fixture.

A spokesman for the school said they purchased them in good faith, after being "approached" by a provider, but the tickets were subsequently cancelled by the club.

Newcastle have now terminated a total of 103 season tickets in recent days for breaching terms and conditions.

The club says the latest situation does not relate to individual supporters re-selling their tickets for St James' in "this instance".

The tour organisers bought the season tickets in the 2015-16 campaign.

United stressed that the continued use and unauthorised resale of season tickets at a "higher package price" was not discovered because there was "no formal contract in place for the tour groups".

"Upon being made aware of this issue, the club took immediate action," a statement read.

"The club have not received any funds above the face value price of these season tickets and have immediately returned the seats for sale to supporters who have entered the official ballot for upcoming fixtures."

The Newcastle United Supporters' Trust previously "welcomed" the club "taking visible action to deter and penalise those who may be profiteering from other fans".

"Along with the rise in ticket prices, according to our annual survey, one of the biggest concerns for Newcastle fans is reduced ticket availability due, not only to high demand, but the selling of tickets through third party sites or other unauthorised means," it added last week.

Newcastle v Barcelona: Magoies apologise after schools sold tickets