The Spanish player spent several years at Zaragoza during the early part of his career before joining Athletic Club Bilbao.
He was recently one of 41 players, coaches and directors named by prosecutors in a match-fixing probe.
The 25-year-old took to Facebook on Tuesday to deny the allegations and pledge his co-operation in any investigations.
“My name has appeared in the legal process that involves Real Zaragoza, a club that I had the privilege to play for between the ages of 12 and 22,” he said.
“My name appears in the 41 names on the implicated list. Before the process commences, I’d like to state that I have never been involved in the manipulation of any result in any game of football.
“If called up, I will testify before the justice system as my conscience is clear. I love the game of football and firmly believe in fair-play on and off the field of play.”
All of the 41 people mentioned in the match fixing case documents were either from Zaragoza or Levante.
It is alleged that Levante’s players were paid to lose a game in May 2011, so that Zaragoza would avoid relegation. Zaragoza won the game 2-1.
Swansea winger Jefferson Montero is the only other Premier League footballer named in the documents. He played for Levante in the game in question.