Canadian border officers acted appropriately and were not responsible for the death of a Nigerian man who died while they were trying to deport him at the Calgary airport in August 2018, Calgary police say.

Bolante Idowu Alo, 49, who wasn't named by police but was identified to CBC News by members of his community, went into medical distress during an altercation with Canada Border Service Agency officers on a plane prior to takeoff.

Alo was on board a KLM flight destined for Amsterdam when he had an altercation with two CBSA officers who were escorting him from the country.

The plane was forced to return to the gate, where the Calgary Police Service's airport unit was called to the scene.

Officers found Alo in medical distress. He died in hospital about an hour and a half later.

Police said Tuesday that the medical examiner determined Alo's death was from natural causes and not due to the actions of the border officials "who were acting in the execution of their duties in a reasonable and appropriate manner."

Alo worked as a taxi driver in Calgary. He had applied repeatedly for refugee status, claiming his life was at risk if he returned to Nigeria and had been engaged in a lengthy battle to stay in Canada.

Because it's not a criminal matter, no further information will be released, police said.