Australia is considering downgrading its representation at a major investment summit in Saudi Arabia amid a global backlash over the alleged slaying of journalist Jamal Khashoggi.

The list of countries and business leaders boycotting the Riyadh event – a three-day conference called the Future Investment Initiative and known as “Davos in the Desert” – is growing in the aftermath of the presumed killing.

The UK trade secretary, Liam Fox, US Treasury secretary, Steven Mnuchin, French finance minister, Bruno Le Maire, Dutch finance minister, Wopke Hoekstra, and International Monetary Fund boss, Christine Lagarde, have all confirmed they are staying at home.

Canada has announced cabinet ministers, government officials and diplomats will all skip the conference.

Among the corporate giants pulling out are the likes of Google, Uber, JPMorgan Chase, Credit Suisse, HSBC, CNN, The New York Times and Financial Times.

Australia’s ambassador to Saudi Arabia and the Austrade general manager are scheduled to attend but Guardian Australia understands the federal government is considering downgrading its representation at the event.

The trade minister, Simon Birmingham, was never intending to attend the event, although the former trade minister Steve Ciobo went last year.

“The Australian government continues to closely monitor the event,” Birmingham told parliament on Thursday.

Saudi Arabia’s ambitious Vision 2030 project – the brainchild of the kingdom’s de facto ruler, Crown Prince Mohammed bin Salman – is heavily dependent on overseas investment.

The Australian Greens and crossbenchers Rex Patrick from Centre Alliance and the Australian Conservatives’ Cory Bernardi this week called for Australia to follow Canada’s example.

“We want a complete boycott of the event to send the strongest possible signal,” Greens senator Peter Whish-Wilson told Guardian Australia.

He said the backlash over the journalist’s treatment is a tipping point, building on concerns about atrocities and human rights violations in the Yemen conflict including the recent bombing of a school bus.

“I think it made people feel sick to the pit of their stomachs, to know this is the kind of thing one of our allies would do to silence dissent within their own country,” Whish-Wilson said.

Save the Children has also urged the Morrison government to rethink its support for the Saudi regime.

The charity is delivering health and education programs in Yemen – the world’s worst humanitarian emergency where 22.2 million people face starvation from a civil war that has been raging for close to four years.

“The world is once again being challenged by how much it can trust the conduct of Saudi Arabia, and Australia must lead by example,” Save the Children Australia chief executive Paul Ronalds told the Guardian.

Austrade overnight has taken down website references to this year’s Saudi summit in which it described the event as a “valuable opportunity to explore investment partnerships … in priority sectors – services and technology, agriculture and food, and resources and energy”.

Khashoggi, a Washington Post columnist, has not been seen since he visited a Saudi Arabian consulate in Istanbul, Turkey on 2 October to pick up paperwork for his upcoming marriage.

Over the past two weeks Turkish officials have leaked evidence that they say proves journalist, who was critical of the Saudi crown prince, was tortured and killed inside the building and his dismembered body driven to the nearby consul general’s house for disposal.

Floodlights and a drone have been deployed in the search for remains at the consul general’s residence after Turkish investigators were finally allowed access to the property.

A key suspect in the case worked in Australia for three months at the Victorian Institute of Forensic Medicine, where he observed autopsies being performed.