Cycling time-trial world champion David Millar, released from custody on Thursday after being held for questioning as part of a doping investigation into his Cofidis team, has been banned from next month's Tour de France.
The Briton is one of several riders barred from the event while they remain under scrutiny.
A spokesman for Tour director-general Jean-Marie Leblanc said on Friday: "In agreement with the (governing body) UCI we have decided that any rider placed under an official judicial investigation or a police inquiry will be barred from the Tour."
He added: "We have told the Cofidis team that this decision concerns riders Cedric Vasseur and David Millar. The decision also concerns all the Italian riders who were placed under investigation in the last Giro d Italia."
An official announcement is expected early next week.
Millar was detained on Tuesday at the request of the investigative magistrate in charge of the Cofidis case before being released but placed under investigation.
Three Cofidis riders have already been charged, including 1992 Olympic bronze medallist Philippe Gaumont, who was sacked by Cofidis after admitting taking and dealing in drugs.
The team withdrew from competition for a month before starting to race again on May 5.
The affair has been called the biggest judicial investigation into cycling since the Festina scandal that erupted during the 1998 Tour de France.
In May, eight cyclists in the Giro d'Italia received early morning visits as part of a probe into doping in sport though investigators said they found no illegal substances.
Millar, a Scot, won the penultimate stage of the 2003 Tour de France - a 49km time-trial - to go with a prologue success in 2000 and a stage victory in 2002.
BBC Online said Millar had never failed a dope test and that he denied a claim he had taken a banned substance.
The three-week Tour de France starts on July 3 with American Lance Armstrong seeking an unprecedented sixth triumph.
Filed by James Boylan
