HALIFAX - A special constable who repeatedly Tasered a mentally ill man who later died in custody denied swearing at him seconds before a struggle ensued and suggested the man made the threatening remark himself.

Special Const. Greg McCormick, who was testifying Thursday at an inquiry into the incident, listened to an audio portion from a video surveillance tape taken at the Halifax police headquarters in the early hours of Nov. 21, 2007.

McCormick and Const. Jonathan Edwards were in the fingerprinting room with Howard Hyde after he was arrested for allegedly assaulting his spouse.

A scuffle broke out some time after McCormick approached Hyde, who had been off his schizophrenia medications for weeks, with a cutting tool to remove a string from his shorts.

Dan MacRury, the inquiry's lead counsel, repeated what was heard on the tape and asked McCormick if he was the one to say, "You're going to be doing the effing dance, Howard."

"It was not me, I would have to say Mr. Hyde," McCormick testified during his first day in the witness box.

Edwards earlier testified that he did not remember anyone swearing, which came seconds before the two officers spilled out into a booking area and McCormick zapped Hyde with the stun gun as three officers tried to pin him to the floor.

Outside the court room, Hyde's sister said she had been able to identify her 45-year-old brother's voice in other portions of the tape.

"I could recognize my brother's voice and what I heard in that line with the effing and dancing remark in my opinion was not my brother's voice," Joanna Blair said.

McCormick said he did not put the remark, which he called "threatening," in his notes. He also didn't record that Hyde said he was sorry as they were wrestling with him or that Hyde was so strong that he allegedly broke a plastic pair of restraints.

The 27-year-old special constable admitted he wasn't sure what was supposed to go in his notes, which are generally a record of what happened on a shift.

McCormick said Hyde, a musician who had a 20-year history of mental illness and many run-ins with the law, had not made any threats to him before the scuffle. But McCormick said he decided to use the Taser because the three young officers were unable to control him during the struggle.

McCormick, who was the booking officer, said Hyde appeared scared when he was approached with the cutting tool and held up both hands in a defensive position.

He said Hyde couldn't get the drawstring out of his shorts because it was knotted at the ends, so they were going to use the tool, which has a 10-centimetre, curved serrated blade on it.

McCormick said the blade on the tool was closed and he was going to use a second, shorter cutting edge to cut the string.

"The look on his face, to me it was the look of scared," he said. "At first he backed up, asking what we were doing and we reassured him we were only cutting off the lace."

Video surveillance shows Hyde flailing as two other officers try to handcuff him after they tumbled on the floor behind a desk. It was then that McCormick reached for the Taser and stunned Hyde without warning.

McCormick said Hyde fell near an exposed drawer with weapons in it, including knives, a mallet, a large butcher knife and scissors.

Hyde was zapped with the Taser repeatedly before officers got control of him in a nearby hallway after he jumped over a desk and fled.

Several officers continued to struggle with Hyde until one realized that he was turning a "blueish-grey colour" and McCormick was unable to find a pulse. They began CPR and mouth-to-mouth resuscitation.

When he regained consciousness, Hyde expressed his fear and McCormick said he tried to reassure him that he was OK.

"And all that I can remember him saying to me specifically is that he was scared," McCormick said before paramedics arrived to take Hyde to the hospital.

The fatality inquiry is examining the circumstances surrounding Hyde's death.