A second officer is now under criminal investigation for assault after a brawl at Manchester Airport, the police watchdog has said.
It comes after a video which went viral online showed 19-year-old Fahir Amaaz allegedly being kicked and stamped on by police during a disturbance near the arrivals hall on July 23.
Mr Amaaz and his brother Muhammad Amaad, 25, were restrained by officers, which led to protests in Rochdale and Manchester city centre amid claims of police brutality.
More footage emerged days later which showed the immediate lead-up to the disturbance, when two female police officers were hit to the ground before Mr Amaaz was Tasered.
Solictor Mr Anwar, brothers Mr Amaad (left) and Mr Amaaz, and their mother Mrs Akhtar face the media
Footage of a police officer kicking Fahir Amaaz, 19, while he was arrested alongside his brotherMuhammad Amaad
In a press conference earlier this week, the family's lawyer claimed the men's mother, Shameem Akhtar, 56, was hit in the face with a Taser by an officer.
In the days after the incident, the Independent Office for Police Conduct (IOPC) announced a Greater Manchester Police (GMP) constable was under criminal investigation for assault in connection with the arrests of the brothers.
In an update on Thursday, the watchdog said a second officer had been advised they were also under criminal investigation for assault. The identities of the officers involved have not been made public by the force.
The officer is also being investigated for potential gross misconduct for alleged breaches of police professional standards including their use of force.
An IOPC spokesman said it had received a further referral from GMP of a complaint, detailing several allegations, from one of the people involved.
The officers could face criminal charges or misconduct proceedings once the investigation has concluded.
IOPC regional director Catherine Bates said: 'It is clear the situation at Manchester Airport was complex and escalated rapidly.
Mrs Akhtar said she was racially abused on her flight to Manchester from Pakistan
Mrs Akhtar, demonstrating her injuries after allegedly being struck at Manchester Airport
MrsAkhtar, 56, appeared tearful as she faced the media this week
'The incident, which resulted in injuries to police officers and members of the public, has caused understandable concern and we are working hard to piece together all of the relevant events on that day.
'In parallel, Greater Manchester Police is investigating whether any criminal offences were committed by members of the public during the initial altercation and the subsequent arrests.
'These investigations are separate, and we are liaising with the Crown Prosecution Service to establish how they can progress in parallel.'
The IOPC spokesman said its investigation will consider whether discriminatory behaviour may have influenced the treatment received.
It will look at the force used against six members of the public in two incidents, the first involving the arrests shown in footage and the second, shortly afterwards, when two other men were arrested and one was Pava sprayed.
It will also consider allegations about the level of care provided to a woman - believed to be Mrs Akhtar - who reported she received an injury during the arrests and a young child present at the time, the language and level of force used by police towards two of the men who were arrested, and the men's subsequent detention in custody.
Four men were arrested on suspicion of affray and assault following the incident. They remain on police bail.
The brothers' solicitor Aamer Anwar this week accused police of leaking information in an attempt to discredit the pair and influence an investigation by the police watchdog into what happened.
Mrs Akhtar was left with a cut and bruising to her face after allegedly being struck by an officer
As Mr Amaad appears to throw a barrage of punches at a male police officer, his brother Fahir smashes a female officer in the face
Mr Amaaz now rounds on the male officer, who has a Taser trained on his brother Mr Amaad, and jumps on his back
In a press conferencae, Mr Anwar said: 'The deliberate attempt by some within Greater Manchester Police or so-called police sources to present a version of events to the media in the immediate aftermath and then to claim publicly that they have cooperated with the IOPC investigation is deeply unhelpful and can be seen as nothing more than a deliberate and cynical attempt to manipulate and mould a narrative of events and untruths.'
He said the family, including the brothers' mother Ms Akhtar, who had arrived at the airport on a flight from Pakistan in which she was allegedly racially abused by a passenger, were 'left devastated and traumatised by the incident'.
Neither the brothers nor their mother spoke to the press.
In a statement, GMP said: 'We understand that there is continued public interest and concern about the criminal investigations being led by Greater Manchester Police into a series of incidents at Manchester Airport in July.
'Four men remain on police bail.
'Our Major Incident Team - led by an experienced senior investigating officer - is making good progress in investigating alleged criminal offences against both the public, and police officers, and we are committed to reaching a conclusion to the investigation as soon as possible in the interests of justice.
'This is a complex case, so we ask for public support in bearing with us while we make sure that inquiries are completed thoroughly.
'We also remain fully committed to supporting the IOPC-led investigation into our officers' actions.'
