Advertisements promoting alcohol products have been spotted on Link Buses around Auckland.
The advertisements for Brothers Beer, Corona and Selaks wines on the buses follow a revelation this month that Auckland Council holds investments in alcohol giants SABMiller and Pernod Ricard.
The bus ads appear to contradict Auckland Transport's advertising policy which says alcohol brands or products are not permitted on its infrastructure, facilities or services.
Alcohol Healthwatch director Rebecca Williams said exposure to alcohol advertising is a "very clear risk factor" for underage drinking - especially when it comes to public transport.
"The evidence is really clear that when young people are exposed to alcohol marketing, it increases the likelihood that they will start drinking if they're not already.
"It also increases the amount consumed by people who already drink."
Williams said the Government needs to do more about alcohol marketing issues as opposed to expecting local councils to deal with it piece by piece.
"It's really important that we take a unified and complementary approach to reducing [alcohol] exposure, but we've got some way to go."
Inner Link passenger Yi Ning, 22, said advertising alcohol on public transport was "pretty bad".
"It's irresponsible and looks really bad for the company. When it's on a bus, children can see it. It's not like it's in a magazine."
Auckland Transport spokesman Mark Hannan said the council body does not own the advertising space on the backs or sides of buses operated by NZ Bus.
He said the current bus advertising arrangement is governed by a formal agreement with outdoor media company QMS Media.
"QMS is responsible for undertaking due diligence around advertising content."
Mr Hannan said new contracts are about to be rolled out, under which Auckland Transport will own all advertising space and will be able to approve or decline advertising.
"Alcohol advertising will not be allowed."
Auckland Transport will take full control of the contracts for buses in the southern area on October 30 this year, followed by west in May 2017, central in August 2017, east in Nov 2017 and north in March 2018, said Mr Hannan.
The advertisements come at a time when Auckland Council is considering the findings of the Alcohol Harm Reduction Strategy review. The strategy, which aims to minimise exposure to alcohol marketing, was reviewed at the council's community development and safety committee meeting on August 3.
This month it was revealed the council holds investments in soft drink, alcohol and tobacco companies only days after it purged fizzy drinks at 21 leisure centres it runs.
One of its investment funds, Janus, holds shares in sugar-heavy brands like Coca-Cola, Hershey and Starbucks, alcohol giants SABMiller and Pernod Ricard, as well as British American Tobacco.
- additional reporting, staff reporter