The Australian electoral commission says a Liberal-linked “grassroots” retirees group campaigning against Labor’s franking credits policy appears to have breached electoral laws by failing to properly disclose the sources of paid advertising.

Guardian Australia revealed on Thursday morning that the Liberal candidate Robert Gunning has helped to orchestrate the Defenders of Self Funded Retirees, a group representing itself as a community-led retiree movement against the Labor policy.

The group has paid for targeted Facebook ads and has built a professional campaign website, neither of which include authorisations telling voters who is paying for the advertising. Its links to the Liberal party are not disclosed in any of its campaign material.

Labor has written to the Australian electoral commission, formally requesting they investigate the revelations. Authorisations of political advertising are designed to make their creators accountable, transparent, and traceable. Failure to authorise can result in fines of up to $25,200 for individuals and $126,000 for a body corporate.

The Labor MP Matt Thistlethwaite wrote to the AEC’s chief legal officer, Paul Pirani, and asked that authorities urgently investigate.

“The Facebook page and website for this group contain no electoral authorisation, contrary to the requirements of the Commonwealth Electoral Act 1918,” he said.

“Furthermore, the Facebook page and website fail to disclose the group’s apparent connections to the Liberal Party. I would be grateful if you could please urgently investigate this matter, and take appropriate action in relation to this group’s failure to authorise the offending Facebook page and website.”

The AEC confirmed to Guardian Australia it would be contacting the organisation. A spokesman said the ads appeared to be in breach of the rules.

“The AEC will contact the organisation because the material in question appears to be ‘paid-for’ advertising that contains ‘electoral matter’ as defined by the Commonwealth Electoral Act 1918 (the Electoral Act) and that is not authorised,” a spokesman said.

“We look into all matters relating to potential authorisation breaches brought to our attention. Our aim is to achieve compliance with the authorisation requirements. To do this, we contact the person or organisation responsible for a social media advertisement to ensure they are aware of the requirements and to require that certain communications containing electoral matter are properly authorised or removed.”

Prof Graeme Orr, an expert in the regulation of democracy, said the ads should have been authorised.

The group has planned targeted campaigns in marginal seats, including in the run-up to the Longman byelection last year, and in Peter Dutton’s electorate of Dickson. The group has taken out print ads, which were authorised by an individual in Albury.

Gunning had initially refused to disclose his involvement in the group when contacted by Guardian Australia, declining to give his name, and saying he was helping the group and was enthusiastic about its cause.

His involvement and the Liberal party links are also not disclosed in a submission made by the group to a Senate inquiry into Labor’s policy. That submission says the group is a “group of retirees who saw the need to encourage individuals to actively defend themselves and their interests in the face of a growing tide of demonisation”.

Gunning later issued a statement to Guardian Australia, through the Canberra Liberals, saying he was “proud to have been involved in a grassroots organisation that is standing up for hard-working Australians”.

“Just like hundreds of thousands of Australians, I have been concerned about Labor’s $45bn tax on retirees since the day it was announced,” Gunning said. “Just like many candidates in every election, I am excited to have the opportunity to stand as a candidate to make sure the voices of my local community are heard.”

The website and Facebook page both direct people to a controversial campaign website associated with the Liberal MP Tim Wilson, who is simultaneously chairing an inquiry into the Labor policy. It has also directed people to a petition against the Labor policy run by Wilson Asset Management, a company headed by a distant relative to the Liberal MP. Tim Wilson also owns shares in Wilson Asset Management.