The family of a Coodanup father who died after being tasered by police say they want justice.
Chad Riley, 40, passed away shortly after being tasered by police officers outside Officeworks in East Perth on Friday.
Police say they were responding to a robbery, which did not involve Mr Riley, when they noticed the father-of-six requiring "urgent medical assistance".
"As police assisted the man he became aggressive and a struggle ensued, with a police officer being injured," a police spokesman said.
"A taser was deployed.
"As the officers continued their attempt to restrain the man he became unresponsive."
Mr Riley's sister Cassandra Riley said her brother is on heart medication and believes the taser contributed to his death.
"The adrenaline, the heart pumping, stress...and then the taser's would've just triggered it off," she told Nine News.
According to Nine News, Mr Riley was arrested earlier in the morning by police and taken to Perth Watch House before being conveyed to Royal Perth Hospital amid health concerns.
His family want to know why he ended up out the front of Officeworks and exactly what happened.
"What happened at the hospital?" Mr Riley's uncle Joseph Northover said.
"Was there a discharge or did he leave?"
An internal police investigation is now underway.
The cause of Mr Riley's death will not be known until an autopsy is carried out.
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