"For whatever reason he brought it up. During the arrest he tried to swallow the bag and then he regurgitated the item," Mr Murray said. The man had swallowed seven grams of powder, which police believe to be methamphetamine, double-bagged inside two snaplock sandwich bags.
The powder, and other drug paraphernalia, has been sent away for testing.
Mr Murray said one gram of methamphetamine had a street value of about $800 to $1200.
"It was sufficient that we've charged him with possession for supply, it was reasonably large," he said.
The man has also been charged with possession of cannabis and other charges may follow.
Mr Murray said the known gang member was based in Waikato, but is formerly from the Hutt Valley.
He could have been going to a Mongrel Mob convention in Porirua.
Alcohol and drug clinic medical officer Richard McGrath said swallowing that amount of methamphetamine was certainly dangerous, but it was unlikely to have killed the man had it leaked.
"It's probably fairly dangerous, but it all depends on the integrity of the plastic bag. If it didn't leak there's probably no harm," Mr McGrath said.
"It would just be a huge dose, but I'm not sure if he would die. It would have a huge stimulant effect, but if he had a medical problem like heart disease it could tip him over the edge."
Mr McGrath said the plastic bags could have blocked the small intestine.
The man appeared in court yesterday and has been remanded in custody until later this week.
