A Geelong radio station's new competition has been slammed as "pornography on training wheels" and criticised for objectifying women.

K-Rock is offering adult store gift packs to the winners of its best beach bum contest, which is heavily promoted on its website.

The public is encouraged to select their favourite from the entries posted online, including women and men in bathers, lingerie and underwear.

The contest has drawn the ire of grassroots activist group Collective Shout, which has recently taken on Geelong-based stationary chain Typo over its porn-themed products.

Collective spokesperson Melinda Liszewski said K-Rock's promotion drew comparisons to a New Zealand radio station's wet T-shirt competition.

"It is basically pornography on training wheels," she said.

"The problem here is the culture that promotes that women aren't complete human beings and are reduced to the sum of their body parts.

"It is unfortunate the radio station is promoting these views."

Ms Liszewski said the group would encourage its 5000-plus members to lodge complaints with the station or the Australian Communications and Media Authority.

Major Sally-Anne Allchin, from Salvation Army Women's Ministries, had concerns over age limits for the competition and the threat of photos of unwilling people being uploaded.

"With it all handled electronically, there is no way of vetting entries," Ms Allchin said. "Who's to say there is not a 13-year-old girl there? You don't see a face, only a butt."

Once an image went online it was in the public domain and could be reproduced or resurface anywhere, Ms Allchin said.

K-Rock program director Leigh Kuhlmann said the station was aimed at both male and female listeners.

"The competition in question, beach bums, was open to both sexes to enter and was not specifically aimed at women at any point as suggested by Collective Voice," he said.

"We did however only receive one entry from a male entrant, which you will see on our website."

Source: Geelong Advertiser