Spurs progressed to the Europa League knockout stages with a 1-0 win against Partizan Belgrade on Thursday, although that feat was overshadowed by a temporary suspension of play in the first half.
The match was halted in the 41st minute after a third individual managed to slip on to the White Hart Lane pitch in what appeared to be an orchestrated PR stunt.
All three men wore t-shirts bearing the name of headphone manufacturer BassBuds, who produce licensed Spurs merchandise.
The company have released a statement condemning the invasions, but Tottenham have removed all mentions of the brand from club channels and related stock from their shops while they investigate.
An official statement from the north London club apologised for the "totally unacceptable behaviour" and the trio now face bans from White Hart Lane.
All three came in on tickets purchased by the same person, while a fourth individual under the same booking was monitored but did not encroach on the field - much to the relief of Pochettino.
"You never know maybe what can happen on the pitch, but the behaviour from these people was only to go in and to show I don't know who or what," the Spurs head coach said.
"I am very disappointed but I think all the club, our supporters, and all people that love the game of football too because this is a very strange situation.
"It is very disappointing but it's important now that we are focused on the next game on Sunday and to be calm and focused on Sunday when we have a very tough game with Everton."
Pochettino may be able to focus on this weekend's return to Premier League action, but the club will be busily investigating the incidents which make the wrong kind of headlines.
As it happens, the sides' previous meeting in September was also shrouded in controversy after Partizan fans displayed an anti-Semitic banner inspired by the Only Fools and Horses logo, with the name changed to 'Only Jews and Pussies'.
It led to UEFA fining Partizan and handing down a partial stadium closure for their next home match, but this time it is Tottenham who look set to face the wrath of European football's governing body.
UEFA delegate Claude Runavot would not speak about the subject when approached by Press Association Sport after the game, although Swiss side Basle were charged after two people encroached on the field during Wednesday's Champions League match against Real Madrid.
The pitch invasions, along with attempts by some to rile the Serbian visitors with Albanian flags, took attention away from what was an entertaining, end-to-end encounter.
Despite already being eliminated, Partizan put in a spirited display and were only undone by Benjamin Stambouli's goal early in the second half.
"I am very pleased with the team and the players," Pochettino said after securing progression from Group C.
"I think it was difficult in the first half to play but in the second half we were better and created a lot of chances.
"It is true that maybe we deserved to score another goal but in the end the job is done
"It is important to go to through to the next round in the Europa League
It is a very good thing."
Source : PA
Source: PA