Former England and Premier League goalkeeper Ben Foster had announced his retirement from football last year
Negreira was the vice-president of the Spanish football federation's refereeing committee from 1993-2018. Barca could face corruption charges in court over the allegations after Spanish prosecutors filed a complaint earlier this month. A statement on Thursday read: "In accordance with article 31(4) of the UEFA disciplinary regulations, UEFA ethics and disciplinary inspectors have today been appointed to conduct an investigation regarding a potential violation of UEFA's legal framework by FC Barcelona in connection with the so-called 'Caso Negreira'."
Sir Jim Ratcliffe and Qatari banker Sheikh Jassim are the frontrunners in takeover from the Glazer family