A teenager with a gold machete has been arrested following a crash and bizarre encounter on a street in Brisbane’s south-east.

A smashed-up Mercedes came to a stop in Alexandra Hills before the young driver emerged, bloodied and in a daze.

Residents came to help, asking the teenager if he was OK as he ran back to his car and tossing out what appeared to be a gold-plated machete about 30 centimetres long.

When an onlooker tried to pick up the weapon, the teenager went back for it and threw it down a drain.

Police were already moving in and the teen was eventually arrested on the road.

Officers were forced to enter the stormwater drain to retrieve the gold knife.

“Oh, look at that – gold plated and all,” one onlooker could be heard remarking.

Minutes before the driver stopped his car, he allegedly smashed into Byrson Martin’s vehicle outside his home.

Martin said he tried to get the teenager’s details but said he seemed agitated.

“I heard a massive bang … ran out and noticed how bad crash was, he was trying to flee the scene straight away,” Martin said.

“I was trying to get his information, he wouldn’t really give it to me.

“He was bleeding and just in a hurry to leave and kept wanting to go to Wellington Point, not sure why.”

The driver was taken into police custody as officers consider charges.