Spanish rider Igor Gonzalez Galdeano, who has led the Tour de France for the last six stages, tested positive for the restricted substance salbutamol but has longstanding medical justfication to use it, Tour officials said Wednesday.

"Traces of salbutamol were found in a July 12 test" at the end of the stage from Forges-les-Eaux to Alencon, Tour spokesman Philippe Sudres told The Associated Press.

The UCI, world cycling's governing body, said he has "the necessary justifications" to take the substance, Sudres said.

Salbutamol, which is taken to treat asthma, is banned unless athletes have a medical prescription for its use.

"The UCI has long had a medical justification for this rider" to use salbutamol, said the Tour's deputy director, Daniel Baal.

Asked about the test, Once team director Manolo Saiz replied: "There is absolutely nothing." He did not elaborate.

Gonzalez Galdeano leads three-time champion Lance Armstrong by 26 seconds in the overall race standings. He finished 13 minutes and 28 seconds behind Armstrong at the end of last year's Tour.