She also claims she initially found used the canister on Castle Street.
The whipped cream gas canister, which contains nitrous oxide, is often used to change the state of mind and provide a short and fast dissociative high.
UPDATE: SOLD
NANG, SIGNED BY SIMON BRIDGES: $666. Message page for more info. Serious enquires only.
Posted by Critic - Te Arohi on Wednesday, 19 February 2020
It is also used to give sedation and pain relief.
Kiwis took to Facebook to make light of Bridges' situation, with some saying it could win him the election.
"His politics might appeal to the wealthy, but his latest social move could get him onside with the hip voters," one person joked.
"Love NZ politicians signing nangs," another said.
A third added: "This is what politics is all about."
A spokesperson for Simon Bridges told Newshub the canister is often used for baking and says Bridges is sure anyone in possession will use it for the right reasons.
Nitrous oxide gas can cause fainting and heart attacks.