Danilo Di Luca's positive drug test and snow hits Giro d'Italia

WINTRY weather and the positive doping test of a previous winner has provided challenges for the Giro d'Italia.

CYCLING-ITA-TOUR-DI LUCA-DOPING

WINTRY weather and the positive doping test of a previous winner has provided challenges for the Giro d'Italia.

Despite the white-out, it proved something of a black Friday for organisers who woke to the news that 2007 race winner Danilo Di Luca was out of the race after reportedly testing positive for the banned blood booster EPO (erythrpoietin).

Amid unseasonably cold conditions and fears for rider security, organisers had announced an alternative route for Friday's stage from Ponte di Legno to Val Martello in Italy's far north-east after heavy snowfall and sub-zero temperatures left the Gavia and Stelvio mountain passes un-raceable.

The Tonale and Castrin passes were brought in as replacements but they too were hit with heavy snowfall, forcing organisers to cancel.

It means Italian Vincenzo Nibali, who stretched his race lead over closest rival, Cadel Evans, to 4min 02sec after winning Thursday's uphill time trial, had one less day to worry about potential challengers.

The Astana team leader was given a further boost in his bid to claim a maiden Giro triumph when organisers made big changes to Saturday's 20th and penultimate stage.

Featuring five mountain passes and a finish on the legendary Tre Cime de Lavaredo, the final day in the mountains was considered the 'Queen' mountain stage of the race.

However severe conditions mean the stage's first three climbs - the Costalunga, San Pellegrino, and Giau - are off the menu, said organisers RCS. Instead, the peloton will race through the Brunico and Dobbiaco valleys to reach Cortina d'Ampezzo, from where the climb to Tre Cime di Lavaredo begins.

The stage's finale, featuring the climb over the Tre Croci and Tre Cime de Lavarado, remains unchanged.

Although on paper Evans has been robbed of the chance to try and close his deficit, the Australian - who admitted on Thursday he was now fighting to keep second place - did not seem vexed.

"Snow still falling here at our Giro Hotel ... and we are at 1000m lower altitude than the proposed climbs,'' Evans, the 2011 Tour de France champion, said in a post on his twitter account.

With little possibility of any real racing in such conditions and amid fears for the peloton, the decision was largely welcomed by the field.

British sprinter Mark Cavendish, who has won four stages on this edition but is at his weakest in the mountains, said: "I remember waking up excited to see snow. Then I became a cyclist. Now I wake up to snow & have to wait to see if I'm excited or not.''

The UCI (International Cycling Union) also supported the decision.

"The organisers have put the security of riders first and the UCI supports their decision,'' said UCI president Pat McQuaid.

"The riders have been racing in very difficult conditions this week, but today those conditions are just too extreme.''

Team Sky came to the race hoping to see their team leader, Tour de France champion Bradley Wiggins, challenge Nibali for the race's pink jersey only for Wiggins to depart early after falling ill.

Sky's sports director Marcus Ljungqvist said: "It just came down to rider safety and there aren't a lot of other options.

"The weather on this race has been the worst that I've seen at a Grand Tour in a long time ... at the end of the day they need to be able to run a normal stage.''

The 37-year-old rider Di Luca, meanwhile, is the second rider from this year's field to leave the race for being implicated in a doping affair.

The Vini Fantini rider was immediately provisionally suspended by the UCI and could now face a lifetime ban from the sport as he has been embroiled in, and banned because of, several doping affairs in the past.

Last week Frenchman Sylvain Georges quit the race after it emerged he had tested positive for an over-the-counter stimulant.

The race finishes in Brescia on Sunday.