Spain's Socialist Party has asked prosecutors to investigate a meeting the country's interior minister had with Rodrigo Rato, the former International Monetary Fund chief under investigation on suspicion of fraud and money-laundering.

The leading opposition party said Thursday it wants authorities to determine if Interior Minister Jorge Fernandez Diaz broke laws by meeting with Rato, who is being probed by officials who work for the Interior Ministry.

Fernandez Diaz' ministry has defended the July 29 meeting as a legitimate discussion of "exclusively personal" matters but requested a parliamentary commission appearance for him to provide a formal explanation.

The investigation involving Rato stem from his time as chief executive of Spain's Bankia bank that was bailed out by the government in 2012.

Rato headed the IMF from 2004 to 2007.