Middlesbrough train on the sprawling grounds of Rockliffe Hall in Hurworth-on-Tees, just outside Darlington.

But this is not your classic training base, hidden away among trees and walled off from the prying eyes.

Rockliffe Hall is also a luxury hotel, spa and golf resort built by Boro owner Steve Gibson. The complex is open to the public.

If you want to sneak in and watch Boro training it would appear you do not have to try too hard.

According to BBC sources, this is what happened late on Thursday morning.

Both clubs have been approached for comment. So far Southampton have made no public statements on the matter.

The supposed spy, who Boro allege to be a Southampton analyst, is said to have parked at the golf club, then walked a couple of hundred yards down a road which leads to the top of a small hill.

The training pitches and golf course are next to each other with just a hedgerow separating them.

While there have been reports that the so-called spy was found hiding in bushes, the real story is apparently no so dramatic.

Sources told the BBC that the accused simply stood at the top of the hill, which slopes down to the training field and gives a clear view overlooking the pitches. Perfect for not-so-covert ops.

At one stage the suspicious individual was pointing his mobile at the training session, while wearing in-ear headphones. Boro staff believe he may have been live streaming the session via a video call.

What happens next sounds more like a comedy sketch than a cunning spy operation.

A member of Boro’s staff approached, say BBC sources, but the person would not identify himself. Then, he quickly deleted some content off his phone before running off into the golf club.

He jogged into the toilets, changed his clothes and hurriedly left the site.

Boro’s photographer took photos – and, allegedly, matched him to a profile on the Saints website. And, of course, the individual was all over CCTV.

Boro staff were furious and quickly reported it to the English Football League (EFL).

Southampton’s squad were not due to fly to the north east until Friday, so if the so-called spy was from the club it suggests an early reconnaissance mission.