Mosquera and Da Pena fail dope test
The two men, who are Xacobeo team mates, tested positive for hydroxyethyl starch, the UCI said.
"Earlier today, the UCI advised Spanish riders David Garcia Da Pena and Ezequiel Mosquera of their Adverse Analytical Findings (presence of hydroxyethyl starch based on reports from the WADA accredited laboratory in Cologne) in the urine samples collected from them at an in-competition test at the Vuelta on 16 Sept. 2010," the statement said.
Hydroxyethyl starch is a plasma substitute that increases blood volume, allowing red cells to continue to deliver oxygen to the body which improves performance.
Mosquera, who could face a two-year ban, told a news conference: "It's a situation that the national bodies need to sort out. In any case, it will be a minor punishment or a warning.
"We will have to try to clear up the issue in the next few days. My conscience is clear. I don't feel guilty."
The new scandal erupted after the UCI said earlier on Thursday that Tour de France champion Alberto Contador of Spain had failed a dope test in this year's race.
"Mr. David Garcia Da Pena and Ezequiel Mosquera have the right to request and attend the analyses of their B samples," the UCI added.
Mosquera, who lost out to Italian Vincenzo Nibali in the Spanish race earlier this month, had just agreed on a two-year deal with Dutch team Vacansoleil.
"The rider from Galicia recently signed an agreement with the Vacansoleil Pro Cycling Team for 2011 and 2012," Vacansoleil said in a statement.
"Vacansoleil has strict anti-doping rules and Mosquera is aware of these. The contract with Mosquera would become valid as from the 1st January 2011. This contract is now up for discussion."
Team manager Daan Luijkx said: "I'm unpleasantly surprised. We have a zero tolerance policy in accordance with anti doping regulations, but first all facts need to be clear to us."