Cycling: Events since the disastrous Tour of 1998 have indicated that the great race has two faces, and both were cast in stark relief yesterday.

On the one hand there are the history and massive popular appeal of the great climbs such as the Col du Galibier, an epic, intimidating backdrop for a quixotic escape by Alexandre Vinokourov, winner here after a 90-mile break over the two toughest mountains in the race.

The other side of the Tour is the hidden world of performance-enhancing drugs, still being used in the race, but by whom and in what quantities no one knows.

Today the Italian Dario Frigo and his wife, Susannah, are likely to be placed under formal investigation for breaching customs laws after Mrs Frigo was stopped and searched by customs men on the A43 on Monday evening following a visit to her husband at his hotel during the rest day.

Tests were yesterday being carried out on the 10 small flasks which police sources said had been found in a thermos flask in her possession. Frigo, who was lying 52nd in the Tour on Tuesday evening, was taken into custody yesterday morning from his team's hotel, the Mercure in Courchevel. He and his wife were released last night.

Frigo's manager at the Fassa Bortolo team, Giancarlo Ferretti, yesterday said he regretted giving the rider a second chance after an episode in 2001 on the Giro d'Italia when a flask of what appeared to be a red blood cell booster was found in Frigo's possession.

The rider confessed he had bought the flask from a stranger at Milan's Malpensa airport after seeing the substance advertised on the internet; when police analysts found it contained only saline solution, it was clear he had been the victim of a sting. He was subsequently banned for six months, but returned to win a stage in the 2002 Tour.

Frigo has never failed a drug test, but he is not the only cyclist who started the Tour to be under suspicion. The Russian Evgeny Petrov did not start Tuesday's stage after a random blood test revealed that he had red cell levels that seemed dubious. Results of a urine test are awaited.

Whatever the doubts about the Italian and the Russian, there is no questioning the direction the race itself is taking. Lance Armstrong will ride south from this fortress town tomorrow into the Alpes de Haute Provence after a dealing with the brace of Alpine stages in a clinical manner that suggests his seventh successive overall victory is more than likely.

"Ask Armstrong," grunted Vinokourov when asked whether the stage win was a gift from the race's master. Armstrong had the answer: "He was not a priority," said the Texan bluntly.

As of Tuesday evening, when he finished six minutes behind Armstrong at Courchevel, the blond, taciturn Kazakh - part mafioso, part elf as one writer has put it - has been out of the overall race, and Armstrong could afford to give him his head. Vinokourov's second Tour stage win after his victory just down the road at Gap in 2003 was a brave riposte after the shipwreck at Courchevel.