Banco Santander, the biggest Spanish bank, faces increased investor scrutiny over lending to property developers after Banco Bilbao Vizcaya Argentaria said its doubtful loans in Spain almost doubled.

'It’s all to do with real estate and developers, and I don’t think Santander is any different,' said Helmut Hipper, a fund manager at Union Investment in Frankfurt, which oversees about €93bn ($130bn). 'There was the perception that there was outstanding quality in BBVA’s loan book, but now it’s back to reality.'