Article continues below advertisementOK! can reveal Prince William and King Charles are "seething and frustrated" over the tangle of legal and constitutional barriers preventing the removal of the ex-Prince Andrew from the royal family's line of succession.Andrew, 66, remains eighth in line to the British throne despite losing his royal titles last year following controversy surrounding his links to convicted s-- offender Jeffrey Epstein, which led to his recent arrest on suspicion of misconduct in public office.