A group of Robin Bain supporters has launched a petition calling on Justice Minister Simon Power to deny his son David Bain's application for compensation for the time he spent in jail after being convicted of the murders of five members of his family in 1995.

Advertisements were placed in major papers today, calling for people to sign up to the petition at a website.

By midday, just over 300 people had signed up.

Bain's legal team is preparing an application for compensation after he was acquitted in June following retrial for killing his parents, Robin and Margaret, and three siblings, Arawa, Laniet, and Stephen at their Dunedin home in June 1994. He spent 13 years in prison.

He could theoretically be eligible for about $1.3 million as Cabinet guidelines state about $100,000 a year is available for people wrongfully imprisoned.

Bain, who recently returned from a three-month European holiday, would have to prove on the balance of probabilities that he was innocent.

"We don't want to go down without a fight," said Robin Bain supporter Vic Perkiss.

"We don't want it (compensation) to just sneak through."

Mr Perkiss said the planned advertisements were carefully worded so as not to run foul of the law.

"We're not going to say he's guilty or not guilty."

Bain supporter Joe Karam said his legal team was "right in the middle" of its application for compensation, which was time-consuming.

He said Bain was staying with him and his partner for "a few weeks" at their Waikato property.

"He's been considering his options, looking into studying classics and drama and thinking about different job opportunities."