Livestrong chairman Jeff Garvey today announced Lance Armstrong had severed all ties with the cancer charity "to spare the organisation any negative effects as a result of controversy surrounding his cycling career".
The Texan was stripped of his seven Tour de France titles after an investigation by the United States Anti-Doping Agency (USADA) found him guilty of using performance-enhancing drugs.
Armstrong resigned as chairman of the charity on October 17 - Garvey was his replacement - as the scandal intensified and the 41-year-old has now stood down from the board of directors.
In a statement, Garvey said: "Lance Armstrong has chosen to voluntarily resign from the board of directors of the Livestrong Foundation to spare the organisation any negative effects as a result of controversy surrounding his cycling career.
"We are deeply grateful to Lance for creating a cause that has served millions of cancer survivors and their families.
"We are beholden to the Armstrong family for the nearly US dollars $7 million in contributions throughout the Foundation's history.
"Lance Armstrong was instrumental in changing the way the world views people affected by cancer.
"His devotion to serving survivors is unparalleled and for 15 years, he committed himself to that cause with all his heart on behalf of the Livestrong Foundation.
"We are proud of Lance's indelible contributions to the global effort to eradicate cancer and his on-going personal commitment to improving the lives of its survivors."
Armstrong has kept a low profile in recent weeks but caused a stir yesterday by posting a picture on Twitter of himself relaxing surrounded by his tainted Tour de France yellow jerseys.
The jerseys were hanging in frames on the walls near an L-shaped sofa, each picked out by an individual lightbulb, with a pair of curtains left open to clearly display the last of them.
Last month, the International Cycling Union (UCI) ratified the sanctions recommended by USADA, who concluded Armstrong and his US Postal team ran "the most sophisticated, professionalised and successful doping programme that sport has ever seen".
All Armstrong's results from August 1, 1998 were expunged from the record books, including his seven consecutive Tour de France "wins" from 1999 to 2005, and the 41-year-old was banned for life.
The World Anti-Doping Agency (WADA) also announced last week it would not appeal against the sanctions, while the International Olympic Committee (IOC) has opened an investigation which could see Armstrong stripped of his road time-trial bronze medal from the 2000 Games.
Armstrong did not cooperate with the USADA investigation and has always denied wrongdoing although he has since removed the line '7-time Tour de France champion' from his Twitter profile.
The fall-out from USADA's verdict has been extensive, with 11 of Armstrong's former team-mates receiving six-month bans after admitting their own doping offences in the course of their testimonies against him.
South African mountain biker David George, who rode with US Postal from 1999 to 2000, was provisionally suspended on Tuesday after testing positive for the banned blood-booster EPO.