Next week a group of artists will present a petition to the National Gallery of Victoria demanding that the gallery sever its ties with Wilson Security, a firm it accuses of “violently enforcing” the incarceration of refugees and asylum seekers on Manus Island and Nauru.

The petition, created by a group calling itself the Artists’ Committee, says that by continuing to do business with Wilson, the NGV “supports systematic abuse”. Since 26 July, more than 950 people have put their names to the petition, including Victorian and interstate artists, regular gallery visitors and arts industry professionals.

“We’re talking about a company whose numerous and well-publicised ethical breaches while managing security at Australia’s reprehensible offshore detention centres amount to nothing less than human rights abuse,” artist Gabrielle de Vietri tells Art Guide Australia on behalf of the Artists’ Committee.

“The instances of sexual assault and gross neglect are on the public record. The fact that human rights abuse has occurred and is still occurring is a view supported by the findings and statements of the UN Human Rights Commission, the UN High Commissioner for Refugees, the Australian Human Rights Commission, the International Red Cross, and Amnesty International,” de Vietri says.

In May, it was revealed that the security contractor was part of a plan to make the detention centre on Manus island as inhospitable as possible. Last year, the Guardian reported Wilson security regularly altered and downgraded reports of self-harm and sexual abuse on Nauru.

Wilson subsequently announced it would no longer provide security services to detention centres on Manus and Nauru when its current contract expires in October 2017. Last year Wilson issued a statement saying that providing such services on those islands was no longer in line with its long-term strategic priorities.

An NGV spokeswoman declined to comment directly on the human rights abuses alleged in the petition. “Currently, Wilson Security is the NGV’s interim security service provider,” the spokeswoman said. “We are in the process of procuring a long-term provider, who will be selected following the refresh of [the Victorian state] government’s security services panel later this year.”

But Ms de Vietri said questions remained for the NGV.

“Who approved the decision and was there any sort of review process? Were those who made the decision to do business with Wilson aware of its human rights record? Does the gallery have any ethical standards that they expect their contractors and suppliers to meet?

We think these are very important questions for a key cultural institution like the NGV,” she says. “As its own vision statement attests, the NGV aims to ‘create an inspiring future.’

It’s hard to see how the gallery can achieve this while doing business with companies like Wilson. We want to know why the tender was not made public and why.”

Another member of the Artists’ Committee, Nina Ross, said the group was aware that Wilson would no longer provide security services at Manus Island and Nauru from October this year.

“Wilson’s decision was not based on ethics,” said Ross. “Rather, it was an attempt to limit the horrendous brand damage the company suffered once the Nauru files were leaked last year. The brand is permanently damaged as far as we’re concerned. This is a company leaving a trail of human rights abuses, producing intergenerational trauma, even today, as it winds up its contracts in offshore detention.”

The petition is expected to be presented to Tony Ellwood, the NGV’s director, on 11 August.