Spain's famed Guggenheim Museum Bilbao has fired its chief financial officer over allegations of embezzlement, museum staff announced Wednesday.

Officials said the famed art museum has also launched legal proceedings against Roberto Cearsolo Barrenetxea, who has headed the Guggenheim Bilbao's finances since it opened to the public in 1997.

The Guggenheim Museum Bilbao, seen here in 1997, draws an estimated one million visitors to the city every year.
(Santiago Lyon/Associated Press)

Cearsolo is accused of embezzling nearly $800,000 over the past decade through small transactions dealing with two companies related to the museum.

Museum officials were alerted to the fact after authorities raised questions about an unrelated financial transaction.

According to Guggenheim Bilbao director Juan Ignacio Vidarte, Cearsolo confessed in a letter and has returned nearly $462,000 to the museum.

He has also pledged to return the remainder and to co-operate with a formal investigation, Vidarte told local media on Wednesday.

The revelation has prompted the museum to undergo an extensive audit of its finances, though officials described the situation as an "isolated case."

Unveiled in 1997, the futuristic-looking Guggenheim Bilbao instantly vaulted the Basque city into the international spotlight.

Designed by Canadian architect Frank Gehry and iconic for its undulating, ship-inspired titanium facade, the river-side modern and contemporary art museum draws an estimated one million visitors — mostly foreign — to Bilbao each year.