A controversial group that claims vaccines cause autism and cancer will again be forced to warn consumers about the information it provides.

The decision is part of an ongoing legal battle that has seen health authorities go all the way to the Supreme Court to try to enforce warnings about the Australian Vaccination Network (AVN).

On Friday the Administrative Decisions Tribunal ruled the AVN must post a “consumer warning” on its website, blog and Facebook page that NSW Fair Trading considers its name to be misleading.

The AVN is fighting a December ruling by Fair Trading that it must change its name, and the warning was put in place on the condition that the group will not have to change its name until its challenge is heard in June.

The President of the Tribunal, Judge K O'Connor said a “prominent” warning will be placed on the websites by close of business on Tuesday saying: “Consumer Warning: NSW Fair Trading has directed the Australian Vaccination Network to change its name because it regards the name to be misleading. The AVN is challenging this direction, and the challenge is currently before the Administrative Decisions Tribunal.”

Fair Trading Commissioner Rod Stowe said the outcome was fair.

“Our contention has always been that from the outside that the website is misleading,” he said.

The decision comes a year after the AVN won a Supreme Court appeal against a decision by the Health Care Complaints Commission, which had ordered it to warn people that its website “should not be read as medical advice”. On the basis of the Commission's decision the AVN had also lost its charity licence. The decision was overruled by the Supreme Court on the basis of a technicality about what types of complaints can be investigated by the Commission.

NSW health minister Jillian Skinner last week introduced legislation – which is expected to pass with support from all sides of parliament – to give the Commission the power to investigate organisations that could pose a wide threat to public health.

She said the amendment would allow the Commission to “proactively initiate its own complaints in respect of serious matters affecting the health or safety of the public.”

A surgeon and spokesman for the group Stop the Australian (Anti)Vaccination Network, John Cunningham, said the group was also pleased with the outcome.

“It's time that the AVN stops being coy about its true goals and aims and starts to be upfront and honest about the one-sided information that it provides,” he said. “The issues at stake with this are not freedom of speech, and not compulsory vaccination, they are about holding people to account to take responsibility for what they say in public”.

The president of the AVN, Greg Beattie, said the organisation was pleased that it would not have to change its name until the hearing in June.

“The way I see it, this is a bit of extra advertising for us,” he said. “[It is showing] this is what's happening to us, and it is being disputed and if it's the right thing to do we will lose, and if it's the wrong thing to do we will win”.