In interviews with former detainees and relatives, newspaper finds 17 detainees were hospitalised after facing abuse.
More than 200 businessmen, princes and government officials were detained in November and imprisoned at the luxury hotel in Riyadh in what the Saudi government said was an anti-corruption drive.
The state has also reportedly taken "large sums" and real estate from Mohammed al-Tobaishi, former head of royal court protocol; Fawaz Alhokair, a businessman; Khalid al-Tuwaijery, former chief of the royal court; Adel Fakieh, former economic minister; and Dabbagh, a businessman who once oversaw the country's foreign investment authority.
Major General Ali al-Qahtani, a top aide to a son of the late King Abdullah, was among those held.
With the prospect of a listing in London and NY receding, sources familiar with the IPO told Reuters that Hong Kong was now emerging as an increasingly likely compromise because Riyadh wants to help Asian nations that are expected to become cornerstone investors. "All those under investigation had full access to legal counsel in addition to medical care to address pre-existing, chronic conditions".
Critics, however, say the arrests were more to consolidate Crown Prince Mohammed's power than to go after the kingdom's endemic corruption.
At least 380 people were held for questioning, while 65 were held in custody at the Ritz-Carlton hotel in the capital Riyadh.
Saudi Arabia's King Salman has promised to build Iraq a football stadium in Baghdad capable of holding about 135,000 people and making it the biggest in the world.
Most of those detained were released after several months.
To leave the Ritz, numerous detainees not only surrendered huge sums of money, but also signed over to the government control of precious real estate and shares of their companies - all outside any clear legal process.
Saudi officials said the crackdown, which came through royal decree, was in response to "exploitation by some of the weak souls who have put their own interests above the public interest, in order to illicitly accrue money".
In an email to the New York Times, the Saudi government denied accusations of physical abuse as "absolutely untrue".
According to former detainees quoted by the newspaper, many are being forced to wear tracking devices on their ankles.