By Paul Osborne and AAP Senior Political Writer
Brisbane Airport has banned three billboard advertising campaigns before the G20 summit, labelling them too political.
The C20 - a civil society forum directly linked to the G20 - wanted to place advertisements in lightboxes at the airport to raise issues such as tackling poverty and improving infrastructure.
But advertising agency oOh!Media, which is under contract to Brisbane Airport Corporation, told C20 organisers they could not because of the political content.
The same policy was applied when banning ads by anti-corruption lobby group Transparency International and a group of environmental organisations wanting to put climate change on the G20 agenda.
BAC corporate relations chief Rachel Crowley said oOh!Media was obliged to apply the corporation's policies, which included a ban on political advertising.
A spokesman for oOh!Media said all artwork needed to be approved by the landowner where the advertisement appeared.
"In our contract with Brisbane Airport, it clearly states that they will not accept any advertising that is deemed to be political," he said.
A C20 spokesman said it was strange the organisation could engage directly with G20 leaders and officials but could not take its message to the public.
Transparency International wanted a billboard that read: "Dirty money not welcome here. G20 it's time to unmaskthecorrupt.com."
"We would hope all political parties would agree with this," TI's Maggie Murphy said of their message.
She said the ban was disappointing because TI had been working with the G20 for the past year to ensure the summit agreed on an anti-corruption action plan.
But both TI and C20 said they will not put up advertising elsewhere in the city.
Advertising in the airport, promoting the Queensland government's Reef Facts campaign, was not considered political advertising under the policy.
"Our judgment is that government advertising on government programs does not constitute advertising with a political intent," she said.
When the state government launched its Reef Facts campaign in March, Environment Minister Andrew Powell said it was to counter "false and extreme claims" about how they were managing the Great Barrier Reef.