Eurozone banks may face added scrutiny and supervisory measures if they do not follow non-mandatory guidance on their capital levels, Daniele Nouy, the European Central Bank's top supervisor said on Monday. While overall capital requirements may not rise after years of capital building, the ECB could suggest to particular banks to set aside more - and they would be well-advised to heed this guidance, Nouy told the European Parliament's economy committee. "This instrument, which we call 'Pillar 2 guidance', would be complementary to Pillar 2 requirements," Nouy told a hearing.