A police officer held down the head of a man, who died hours after his release from custody, because he feared he would spit at him, a police disciplinary panel has heard.
Mohamud Hassan, 24, died on 9 January 2021 after being found unresponsive in his Cardiff flat, having been arrested and released the previous evening.
The disciplinary panel has retired to consider a gross misconduct allegation.
Officer A is accused of using excessive force.
The sergeant was on duty at Cardiff Bay Police Station, where Mr Hassan had been detained on suspicion of breaching the peace.
The panel, sitting in Bridgend, heard how before Mr Hassan's arrest he had a cut to his face and spat from the window of his flat towards officers responding to reports of an assault.
He appeared to be intoxicated and was shouting that he was "having a fit" and that officers were "trying to kill him."
A spit hood was put over his head, but in the police van he was able to move his handcuffs from his back to his front and remove the hood, which was covered in blood and saliva.
Mr Hassan's death led to a series of demonstrations including a large scale protest outside Cardiff Bay Police Station.
The hearing was previously told an investigation by the Independent Office of Police Conduct "did not find that time spent in custody was a contributory factor in his death".
Police bodycam footage showed Mr Hassan kicking the van, banging his head against the panels and shouting abuse at the two arresting officers.
Officer A told the hearing he was walking in front of Mr Hassan with two officers either side of him towards a cell at the station at the time of the alleged misuse of force.
Officer A said he heard Mr Hassan preparing to spit and considered it "a violent act" so he told the hearing he held Mr Hassan's head down to stop him spitting at the two officers and himself.
Jonathan Walters, from appropriate authority with South Wales Police asked the officer if he resented Mr Hassan for being "belligerent and uncooperative".
Officer A replied: "Absolutely not - 100% the hocking noise triggered my actions."
When asked why another spit hood was not put over Mr Hassan's head, he said he thought it might have "escalated the situation".
The hearing was told Officer A was an experienced custody sergeant who had received a commendation for actions during his policing career.
Mr Walters said there was no doubt that Mr Hassan was "aggressive and abusive" but that Officer A's use of force was "gratuitous".
Dean George KC, for Officer A, said the incident happened during the height of the pandemic when "courageous" officers were "risking life and limb in a way they had never before".
He said the evidence presented was "nowhere near gross misconduct".