The family of the man who was kicked in the face by an armed officer have appealed for calm after a second night of protests over the “barbaric” arrest at Manchester airport.

Paul Waugh, the Labour MP for Rochdale, said the “traumatised” family wanted to make clear they had “no political agenda whatsoever” and called for “calm in all communities”.

Video footage of an armed officer kicking 19-year-old Muhammed Fahir in the face as he lay prone on the ground has provoked widespread revulsion and triggered two nights of protests in Rochdale and Manchester.

The Independent Office for Police Conduct (IOPC) has launched an investigation into the officer’s actions, including his use of Pava spray on a second man. The officer has been suspended from all duties.

Investigators will meet Fahir’s family for a second time on Friday after acknowledging the “widespread shock and concern” prompted by the footage of the incident at Manchester airport on Tuesday night.

Fahir’s solicitor, Akhmed Yakoob, said on Friday that the teenager had been referred to a neurologist after a CT scan showed a cyst on his brain.

Asked by the Guardian whether he believed the alleged brain injury was linked to the incident, he said: “That is something a medical professional would have to answer but as far as I know I’ve spoken to the consultant and they’re saying it could be related to the injuries at the airport.”

Waugh said on Friday that the family’s priorities were their health and making sure that “justice is done and is seen to be done”.

He told BBC Radio 4’s Today programme: “The family also wanted me to make crystal clear [that] they’ve got no political agenda. They do not condone political violence and they do not want to take part in any protests.

“And they wanted me to appeal for calm on their behalf. And I hope that appeal is heeded not just in Rochdale, but in Manchester as well.”

Anti-racism protesters gathered outside the office of Andy Burnham on Thursday night, chanting “racist GMP, shame on you” as they briefly stopped traffic. It followed a large gathering outside Rochdale police station the previous night.

Waugh said the footage of the police officer’s incident was “disturbing” but said it was “important not to rush to judgment based on a few video clips”.

The newly elected MP said he had met Greater Manchester police (GMP) and been shown more footage of the incident than had been publicly released.

GMP has said three of its officers were assaulted, including a female officer who suffered a broken nose as they responded to reports of an assault at Terminal 2 at 8.25pm on Tuesday.

Two of the men were arrested on suspicion of assault, assault of an emergency worker, affray and obstructing police. Two other men were arrested on suspicion of affray and assault of an emergency worker.

The IOPC is analysing police body-worn footage of the incident and has opened a dedicated reporting line for any witnesses to give information.

Waugh said it was important to let the watchdog carry out its investigation: “The key thing now is that that evidence and that process is allowed to get on and be allowed to carry on its work without any interference whatsoever, and it’s seen as utterly independent.”