The supervisor entered the tunnel to find the man had defecated on the road.
Asked for an explanation, the man replied: "How many times do you get a chance to f***ing shit in the tunnel?"
An incident report said "the guy was clearly drunk" and police were called.
Police quickly arrived on both sides of the tunnel and within five minutes had queried the man.
"A few details were taken and the man was free to go."
It was decided the tunnel could not open until the disgusting deposit was cleaned up - but there were no volunteers for the task.
The supervisor "reserved his rights" and declined to shovel up the faeces, instead telling the Operations Centre to have contractors from Fulton Hogan remove it.
A Fulton Hogan crew arrived at roughly 6.30am and spent about five minutes cleaning up the mess.
Traffic was allowed through at 6.45am, 45 minutes later than would otherwise have been the case.
The incident report showed transport authorities had a forgiving attitude to the opportunistic pooper.
"This was a rare incident in which a drunk man made a poor decision outside of the project team's control which resulted in delay of the tunnel reopening."
The supervisor's contention that shovelling poo was not in his job description was vindicated.
"It can be argued that the [supervisor] should've shovelled the faeces but it is well within [his] right not to do so as this is not within his scope of works."
There was no suggestion the man was charged but police commonly issue pre-charge warnings to drunk people who commit minor offences and have no criminal record.
At the time, a New Zealand Transport Agency spokesman supported the decision to delay the tunnel opening.
"It's important to clean it up while it is still in one place, before tyres start to track it all over the place."
However, the agency also said it would review its response times, in case a similar event ever happened again.
- NZME
