Forensic pathologist Martin Sage, who is not connected to the case, said the condition was usually seen in people who used drugs like methamphetamine and they often had extreme body temperatures because they were "literally hopping".
Otago University professor Pete Ellis, from the Department of Psychological Medicine, said it was rare in New Zealand for patients to die of the syndrome, but not unheard of. "If you've been charging around and not eating or drinking and exerting yourself to an extreme extent, maybe hitting people or actively fighting restraints, it could lead to fatal cardiac events," he said.
The Independent Police Conduct Authority (IPCA) is expected to release a report into Taitoko's death within the next two months and would not comment on the case when contacted by the Herald on Sunday.
Peter Williams QC, who is acting for Taitoko's family, said he had not been informed of the cause of death.
Police would not comment on the case because a criminal investigation into his death was continuing. Taitoko died after being arrested at his Manurewa home in February last year. Police said he was "violent and aggressive" and family members had tried to restrain him.
He was in a monitored cell and a police doctor assessed him, but four hours later his breathing became laboured and he died despite efforts to revive him.