Saudi Arabia's de facto ruler is using the oil-rich kingdom's sovereign wealth fund to bankroll vanity projects linked to a host of rights abuses, Human Rights Watch said on Wednesday.

A 93-page report from the New York-based group describes how Crown Prince Mohammed bin Salman has asserted control over the Public Investment Fund (PIF), which now manages assets worth around $925 billion compared with $84 billion a decade ago.

It accuses the 39-year-old of seizing companies and assets from elite Saudis rounded up during high-profile anti-corruption operations beginning in 2017, the same year he became first in line to succeed his father King Salman.

Some of those companies, it says, later ended up under PIF control.

The report also ties PIF-owned companies to abuses at some of the most prominent megaprojects under Vision 2030, Prince Mohammed's programme to diversify the Saudi economy.

Those include evictions at NEOM, a planned futuristic mega-city in the Saudi desert, and demolitions to make way for luxury shopping and tourism developments in the coastal city of Jeddah.

"Through the PIF, Crown Prince Mohammed has consolidated unprecedented state economic power under his sole decision-making with few, if any, constraints on how he deploys his nation's wealth meant to benefit the entire Saudi people," the report says.

"Saudi Arabia's most marginalised people -– migrant workers, rural communities, poor and working-class residents –- have borne the brunt of abuses stemming from the Crown Prince's most abusive PIF-backed projects."

Neither the Saudi government nor the PIF responded to AFP's request for comment.

World Cup bid

Many of the abuses alleged in the HRW report have been described elsewhere.

The United Nations special rapporteur on extrajudicial killings published a report in 2019 stating that two planes belonging to PIF-owned Sky Prime Aviation transported the hit squad that killed journalist Jamal Khashoggi in the Saudi consulate in Istanbul in 2018.

Khashoggi's murder sparked an international outcry that temporarily threatened to isolate Prince Mohammed.

But Prince Mohammed has "managed to drastically change this period of brief international isolation... to become a central figure on the world stage", the report's author Joey Shea told reporters this week.

Now there are "very few businesses fearful of going to Saudi Arabia".

The report urges businesses to avoid working with the PIF "when serious adverse human rights impacts have been identified as unavoidable".

The PIF has played a major role in improving Saudi Arabia's reputation globally, including through splashy investments in sports that have drawn the world's top footballers, tennis players, golfers and Formula One to the Gulf kingdom.

That strategy is expected to get a ringing endorsement next month when the FIFA Congress is set to formally approve Saudi Arabia's bid to host the World Cup in 2034. Saudi Arabia is the only candidate.

"Getting (the) 2034 World Cup to Saudi Arabia is arguably one of the most important events for Mohammed bin Salman," Shea said.