The investigation into allegations seven-time Tour de France champion Lance Armstrong used performance-enhancing drugs has been closed.
Armstrong, 40, will face no charges after the federal probe which ended on Friday after nearly two years.
The American has vehemently denied the allegations he doped during his illustrious career and investigators have failed to prove otherwise.
In a statement after the investigation was closed, Armstrong said he was looking forward to getting on with his life without the distraction.
"I am gratified to learn that the US Attorney's Office is closing its investigation," he said.
"It is the right decision and I commend them for reaching it. I look forward to continuing my life as a father, a competitor, and an advocate in the fight against cancer without this distraction."
A grand jury was given evidence by federal prosecutors and heard testimony from Armstrong's former team-mates in Los Angeles, but a reason for closing the investigation was not given on Friday.
US attorney Andre Birotte Jr said in a release his office was "closing an investigation into allegations of federal criminal conduct by members and associates of a professional bicycle racing team owned in part by Lance Armstrong."
Authorities looked at whether a doping program had been established for Armstrong's team while, for some part of the time, it received sponsorship from the US Postal Service.
Armstrong was never questioned in front of the grand jury, with the prosecutors handed the task of determining whether he or other team members violated federal conspiracy, fraud or racketeering charges, or used drugs to aid their performances.
Former US Postal riders Frankie Andreu, Floyd Landis and Tyler Hamilton have all previously accused Armstrong of doping.
Armstrong, who won every Tour from 1999 to 2005, could not be out in the clear yet though, with the US Anti-Doping Agency (USADA) interested in obtaining the information gathered in the investigation.
"Unlike the US Attorney, USAFA's job is to protect clean sport rather than enforce specific criminal laws," USADA CEO Travis Tygart said in a statement.
"Our investigation into doping in the sport of cycling is continuing and we look forward to obtaining the information developed during the federal investigation."