The families who flew on private jets can not gain access to their bank accounts, even wives and children have been forbidden to travel.
Their wives and children have reportedly been prevented from travelling.
Some of those held at Riyadh's luxury Ritz-Carlton hotel were deprived of sleep, roughed up, interrogated with their heads covered and pressured to hand over large assets, the report said, citing relatives and associates of detainees.
In November, Saudi Arabia launched an anti-corruption purge, arresting hundreds of the country's elite, including billionaires, government ministers, and royal family members. Most detainees have been released but witnesses say they are not really free, living in fear and uncertainty.
The government has yet to actually seize numerous assets, leaving the former detainees and their families in limbo.
"I would guess it is about evens that there will be no worldwide IPO", one high-level source said, according to the agency.More news: Vermont Unemployment Rate Low As Labor Shortage Builds
While evidence of such abuse has been slow to emerge, Western governmental officials are said to be confident of the credibility of these reports.
One case involved a Saudi military officer who died in custody.
A final decision will be made by Mohammed bin Salman, who oversees the kingdom's economic and oil policies. His skin showed other signs of physical abuse, the person said.
The report alleges al-Qahtani's "neck was twisted unnaturally as though it had been broken" and his body also had burn marks, which were believed to be a result of electric shocks.
Saudi officials approached by the Times over the allegation said: "All allegations of abuse and torture of those investigated during the anti-corruption proceedings are absolutely untrue". "All those under investigation had full access to legal counsel in addition to medical care to address pre-existing, chronic conditions".
Major General Ali al-Qahtani, a top aide to a son of the late King Abdullah, was among those held.
Saudi Crown Prince Mohammed bin Salman is "pleasant, open-minded, cultured and visionary", Coptic Pope Tawadros II said in a Monday statement.