The decision follows a request by the anti-corruption public prosecutor last week and will see BBVA investigated on charges of bribery, disclosure secrets and corruption in relation to the company’s alleged dealings with former police chief Jose Manuel Villarejo.

In a statement, BBVA's Executive Chairman Carlos Torres reiterated the company's "firm commitment to clarifying the facts and complying with the law".

News websites El Confidencial and Moncloa.com reported in January that BBVA had hired Villarejo's firm, Grupo Cenyt, to investigate officials of construction company Sacyr  as part of efforts to stop a takeover bid by the company in 2004.

The investigating judge in charge of the case earlier in July expanded his investigation to eight former or current BBVA employees, but none belong to the bank's current board.

(Reporting by Sam Edwards and Jesus Aguado; editing by Emelia Sithole-Matarise and Deepa Babington)