The wife of a maths teacher sacked after allegedly assaulting his daughter has told an employment tribunal that both were left bleeding after a row.
David Aldridge claims unfair dismissal from the school
But Geta Aldridge said her husband had never punched or kicked their daughter, who was 16 at the time.
David Aldridge was suspended from Olchfa Comprehensive School in Swansea in December 2005 and later dismissed.
He is claiming unfair dismissal, and the Cardiff tribunal's decision will be announced in several weeks.
His daughter Sioban - who was a pupil at the school - allegedly told friends he had punched and kicked her, the tribunal has been told.
A police investigation was carried out and Mr Aldridge was arrested but no charges were brought. He was later dismissed by school governors after an internal investigation.
The teacher, who was also head of year nine, previously admitted there had been an "exchange of slaps" between himself and Sioban.
Mrs Aldridge told the tribunal both her husband and daughter were cut during the argument, which started after Sioban returned home late for the second night in a row.
Mrs Aldridge said: "Both of them sustained cuts. I gave them toilet paper to mop up the cuts on their faces."
The tribunal heard that her daughter had left the house after the argument, on what Mrs Aldridge described as a "fraught" night for the family.
Mrs Aldridge denied her husband had ever punched or kicked their daughter and told the tribunal: "I'm a mother, and I'm telling you that this never ever happened."
She said she found such violence "absolutely horrendous, to say the least".
The tribunal has previously heard that Sioban underwent a medical examination after the alleged assault and injuries, including bruises, were found on her body.
Mrs Aldridge said her daughter had sustained injuries playing sports. She also told the tribunal that her daughter had been injured in a car crash two weeks before the incident.
When asked by Peter Maddox, representing the school governors, why her daughter later denied telling friends she was assaulted, Mrs Aldridge said she did not know.
She said: "As a mother sitting here, I find it very hard, because I can't explain it."
Making his closing submissions, Richard Kember, representing Mr Aldridge, said his client had 31 years of "impeccable service" as a teacher and was highly-regarded by his colleagues.
He said Mr Aldridge had always denied the allegations that he had assaulted his daughter on December 10 2005, and on previous occasions.
He told the tribunal: "There were significant and fundamental flaws in this investigation, flaws which were such to make it unfair and to be unreasonable."
Mr Kember said Mr Aldridge was not allowed to give his version of events when he was suspended, and that the following investigation had not been carried out correctly.
Mr Maddox said it was more likely Sioban had been telling the truth to her fellow pupils than the school's disciplinary committee "because of the way the disciplinary procedure had gone".
He argued that all correct procedures had been followed, and that suspending Mr Aldridge was the "only realistic thing that could have been done in the circumstances".
Mr Maddox said the panel had decided the matter was so serious that it amounted to gross misconduct, and that Mr Aldridge's position in the school was therefore "untenable".
The decision of the employment tribunal will be made in four or five weeks, said chairman Rachel Davies.