Four-time Tour de France winner Chris Froome has been cleared of any wrongdoing in the case of his adverse analytical finding (AAF) for salbutamol.
The case has been ongoing since last September, when Froome was found to have more than the permissible amount of asthma drug salbutamol in his system when he returned a urine sample during the Vuelta a Espana.
The Team Sky rider has always maintained his innocence and cycling's governing body said on Monday: "The Union Cycliste Internationale (UCI) confirms that the anti-doping proceedings involving Mr Christopher Froome have now been closed."
The decision comes just before the start of the Tour de France, which gets underway on Saturday, and Froome is now free to bid for a fifth victory.
Froome says he only ever ingested the permitted dosage of the bronchodilator and, as a result of the UCI decision, he keeps his 2017 Vuelta a Espana title.
He is the first British rider to have won the Spanish Grand Tour, and the first since Bernard Hinault in 1978 to win the Vuelta a Espana and Tour de France in the same year.
The UCI statement added: "The UCI has considered all the relevant evidence in detail (in consultation with its own experts and experts from WADA).
"On 28 June 2018, WADA informed the UCI that it would accept, based on the specific facts of the case, that Mr Froome's sample results do not constitute an AAF.
"In light of WADA's unparalleled access to information and authorship of the salbutamol regime, the UCI has decided, based on WADA's position, to close the proceedings against Mr Froome.
"Whilst the UCI would have obviously preferred the proceedings to have been finalised earlier in the season, it had to ensure that Mr Froome had a fair process, as it would have done with any other rider, and that the correct decision was issued.
"Having received WADA's position on 28 June 2018, the UCI prepared and issued its formal reasoned decision as quickly as possible in the circumstances.
"The UCI understands that there will be significant discussion of this decision, but wishes to reassure all those involved in or interested in cycling that its decision is based on expert opinions, WADA's advice, and a full assessment of the facts of the case.
"The UCI hopes that the cycling world can now turn its focus to, and enjoy, the upcoming races on the cycling calendar."