ZURICH: Former FIFA anti-corruption adviser Mark Pieth says Sepp Blatter should face a criminal investigation for selling under-valued World Cup television rights to Jack Warner. Pieth, a Swiss professor of criminal law, says 'Blatter has to defend himself against a form of embezzlement charges.' Swiss broadcaster SRF has published a Blatter-signed FIFA contract from 2005 that gives the Warner-controlled Caribbean Football Union rights to the 2010 and 2014 World Cups for $600,000. Warner reportedly sold the rights through a family company for around $20 million. Now indicted in a US probe of soccer corruption, Warner previously claimed he secured cheap World Cup rights for helping Blatter win presidential elections. A separate Swiss case targets 'criminal mismanagement' at FIFA. Pieth says: 'They have prima facie evidence. That means they have to open an investigation.'