The La Liga club face being banned from the UEFA Champions League over the claims which were already being probed by Spanish prosecutors.

Jose Maria Enriquez Negreira, the former vice-president of Spain's Referees Committee, is at the centre of the case.

It is claimed that Barcelona paid Negreira and a company owned by him millions of dollars between 2001 and 2018.

A lawsuit has targeted the club, along with former Presidents Josep Maria Bartomeu and Sandro Rosell.

Barcelona have denied wrongdoing and no evidence of match manipulation or favourable decisions have been produced.

The club has claimed that it paid for technical reports on referees and never tried to influence any games.

However, the opening of a probe by Europe's football body UEFA will be seen as a further blow.

"In accordance with Article 31(4) of the UEFA Disciplinary Regulations, UEFA ethics and disciplinary inspectors have today been appointed to conduct an investigation regarding a potential violation of UEFA's legal framework by FC Barcelona in connection with the so-called Caso Negreira," UEFA said.

"Further information regarding this matter will be made available in due course."

Current Barcelona President Joan Laporta, now in his second spell leading the club, has denied that referees were bribed and has launched an internal investigation.

La Liga chief executive Javier Tebas has claimed that Laporta should resign if he cannot explain the payments or if the charges are proven.

Barcelona is one of the most famous football clubs in the world but have recently been told by La Liga to reduce its squad budget by €200 million (£177 million/$218 million).

They have won La Liga 26 times and the UEFA Champions League five times.

Four of the Champions League wins were between 2001 and 2018, the time period in question when the club won La Liga nine times.