PC 4105 Hardacre of Lancashire police's armed response unit said he thought Ronald Robinson had taken drugs when he collapsed and had to be rushed to hospital in the middle of being arrested on March 11 2021.
In fact, he had attempted to swallow a 7cm by 4cm plastic bag containing class A drugs, which became stuck in his throat.
At an inquest today (June 21) PC Hardacre said: "He didn't make any gagging sounds, he didn't make any coughing motions, there was no indication at all that he was choking."
"In his mouth there was nothing visible at all. Nothing that we could see in the back of his throat."
Mr Robinson, 56, of Queen's Promenade, had been pulled over by PC Hardacre and PC 6968 Reeve at around 5.30pm on Knowle Avenue, North Shore, after the Hyundai car he was driving in was reported stolen.
It was then he tried to swallow the plastic bag, which contained eight packages of heroin, five packages of crack cocaine, and five packages of an unidentified brown substance.
PC Hardacre said: "I saw him put a small ball-shaped object into his mouth.
"We were trying to get Mr Robinson to spit out whatever he had put in his mouth, but he was clenching his jaw the whole time... he just wouldn't spit it out."
A struggle broke out, resulting in Mr Robinson being detained on the ground.
PC Hardacre said: "After we had handcuffs on him and sat him up, PC Reeve sat with Mr Robinson and told him to spit out whatever he had in his mouth, and he started to go downhill from there. His response began to become less and less.
"We requested an ambulance and continued to monitor him.
"He started to become less responsive so PC Reeve suggested we put him on his side.
"I retrieved the para-bag and the defibrillator. By the time I got back PC Reeve had got Mr Robinson on his side and was removing his handcuffs. At this point he wasn't a person we wanted to arrest, he was a person we wanted to help."
He added: "I thought it looked like he had swallowed some drugs and it was taking effect."
PCs Hardacre, Reeve, and another police officer, 5535 Crowley, carried out CPR on Mr Robinson at the scene until paramedics arrived at 5.53pm.
Nearly 10 minutes later, the plastic bag was discovered and removed from his airway.
Mr Robinson was taken by ambulance to Blackpool Victoria Hospital, where he was pronounced dead due to acute upper airway obstruction at 6.38pm.
One witness, Steven Logan, who had been working near Knowle Avenue, said: "I saw (Mr Robinson) had been restrained quite forcefully. Excessively, in my opinion. I would use the same force to protect myself if I was attacked - putting my arms around someone's neck from behind and squeezing."
PC Hardacre said the force used to restrain Mr Robinson was appropriate as he was resisting arrest.
The inquest continues.