Sources told NBC New York that the designation means Dominique Strauss-Kahn is checked every 15 to 30 minutes and has been given a special prison jumpsuit and shoes that have no laces.
The IMF chief, a man accustomed to luxury hotel suites and first-class plane travel, is making his home the notorious Rikers Island jail.
Strauss-Kahn was transferred from a detention center attached to the Manhattan Criminal Court to Rikers Island on Monday and held in protective custody in an 11-by-13-foot cell, a spokesman for the New York City Department of Correction said.
Defense lawyers said they were considering whether to appeal the bail ruling. Should the judge reaffirm the denial of bail, Strauss-Kahn could be held at Rikers throughout any trial.
Strauss-Kahn checked into Rikers Island's West Facility, the smallest of the 10 jails in the complex and designed to care for inmates with communicable diseases, the spokesman said.
Although Strauss-Kahn is healthy, the design allows him to be separated from any inmates who might seek fame by attacking someone famous.
He is one of 25 to 30 inmates in the facility but will be kept from other inmates when he leaves his cell to stretch his legs, watch television in the common room or exercise.
Lights go out at 11 p.m. He is allowed three visitors a week aside from his lawyer and he will be given one hour a day for exercise.
Strauss-Kahn was issued bedding and a standard toiletry kit of a drinking cup, soap, shampoo and toothpaste, the spokesman said.
A judge in New York City had denied bail to IMF chief Dominique Strauss-Kahn, who is in court facing charges of sexually assaulting a hotel chambermaid in Times Square on Saturday evening.
The judge said Strauss-Kahn, who tried to flee the country on a Paris-bound Air France jet after the alleged assault, is a flight risk. He was arrested by New York Police Department before the aircraft departed.
Strauss-Kahn has been officially charged with a criminal sexual act, unlawful imprisonment and attempted rape. The 32-year old victim identified him in a line-up.
Strauss-Kahn has pleaded innocent.
Strauss-Kahn's defense lawyer Benjamin Brafman said his client will be exonerated.
He intends to vigorously defend these charges and he denies any wrongdoing, Brafman said.
On Sunday, Strauss-Kahn underwent medical examinations to determine if there was any physical evidence tying him to the assault of the maid.
News of the arrest has roiled France and Europe.
Strauss-Kahn was slated to run for president of France in next year's elections under the Socialist banner.
The president of the French Socialist Party Martine Aubry said the arrest was a thunderbolt, but added Strauss-Kahn should be presumed innocent.
However, Strauss-Kahn's problems may only be beginning.
A French writer named Tristane Banon, 31, said she might file a complaint against him for an alleged sexual assault that occurred in 2002.
We're planning to make a complaint, Banon's lawyer told Agence France Presse.