The town of Port Arthur wants to forget killer Martin Bryant

Twenty years ago a young, blonde-haired man who drove a yellow Volvo with a surfboard strapped to the top killed 35 people at Port Arthur, a historic tourist town in Tasmania.

It was the worst mass shooting in Australia's history and for many years it has defined the town, although among locals it is a sensitive, almost taboo topic. The gunman, Martin Bryant, is one of the country's most notorious villains, but his name is rarely spoken in Port Arthur.

So people were surprised and dismayed in March this year when an actor drove a yellow Volvo around the massacre site at the behest of a major Australian television network.

"To hire a yellow Volvo with a surfboard on the roof and a have a blonde, long-haired man drive around the site so they could film it was an extraordinarily horrible thing to do," said local mayor Roseanne Heyward.

The media rehashing of Australia's Port Arthur shooting massacre in the lead-up to Thursday's 20th anniversary has been upsetting for the community, leaving many people keen for the day to be done.

Since March there has been an outpouring of reports on the massacre, boasting of never-before-seen material, first-time accounts, graphic retellings and television re-enactments.

Capping that was news this week of a graphic movie of the massacre, playing to conspiracy theories Bryant wasn't the killer, that is due to start filming this year.

Stephen Large is chief executive of the Port Arthur Historic Site, the former penal colony and world heritage-listed site where Bryant shot most of his victims.

Mr Large said the television re-enactments and rehashing of the massacre were disappointing, particularly the Volvo drive-by re-creation.

"That rocked quite a few people here and certainly upset a lot of people in the local community, and I'm sure a lot of people that were directly affected by 1996," Mr Large said, adding that any requests to film a movie at the site would be assessed on their merits.

Prime Minister Malcolm Turnbull heads the dignitaries attending a Thursday ceremony marking 20 years since the massacre.

The two-hour ceremony, the first at the site since the 10th anniversary, will be broadcast live on two of the country's television networks.

Former prime minister John Howard, who moved swiftly and decisively to ban the possession, use and importation of semi-automatic and automatic rifles following the shootings, will also be among those at the ceremony.

Despite the reluctance of some locals to mark the tragedy, many victims' relatives were determined to hold a milestone ceremony. Some survivors will return to the site for the first time since that Sunday in 1996.

Mayor Heyward said compassion for these people made the service a necessity. "How could you refuse them?" she asked.

"But we have moved on, we'll never forget, but we have to get up every morning and get on with our lives and that is what this community has done."

Martin Bryant, now aged 48, is serving 35 consecutive life sentences.

Many people object even to the use of Bryant's name, with local media often bombarded with complaints if he is mentioned in reports.

Tasmania Times news website editor Lindsay Tuffin said Tasmanians wanted Bryant excised from memory.

"There is no doubt that they do not want to even ponder it," he said. "They just wish he never existed."

The feeling is so strong that visitors to the Port Arthur Historic Site are usually urged not to ask questions about the massacre.

"Rather than ask a guide, please read the plaque at the Memorial Garden or pick up a brochure at the Visitor Centre," an instruction reads.

Hobart Mercury editor Matt Deighton said local media approached the topic in a completely different way to mainland publications.

"It's as sensitive an issue as I've experienced in 26 years of journalism," he said.

"Our coverage will be subtle and respectful, focusing on the anniversary and how the community has tried, at varying levels of success, to move on."

Thursday's ceremony may be unsettling for those who would rather forget the senseless violence in 1996.

But Stephen Large from the Port Arthur Historic Site is hopeful that it will be a positive experience for victims and the community.

"There are some people coming who we know haven't been back to the site for 20 years so it will be particularly poignant for them and we hope it's worthwhile for them," Mr Large said.