Faustino Asprilla labelled Real Madrid a "team of rats" after the Champions League titleholders were beneficiaries of some controversial decisions against Bayern Munich.
Madrid booked their spot in the semi-finals on Tuesday thanks to a 4-2 extra-time win at home to Bayern, who crashed out 6-3 on aggregate in the Spanish capital.
Cristiano Ronaldo scored a hat-trick but the return leg was overshadowed by the referee's performance after Viktor Kassai controversially showed Arturo Vidal a second yellow card for what appeared to be a fair challenge in the 84th minute with Bayern leading 2-1 on the night before allowing two offside goals in extra time.
And former Colombia international Asprilla - who played for Newcastle United and Parma - did not hold back, writing on Twitter: "No more robberies for Real Madrid, they are a team of rats."
Asprilla, 47, was among the long list of critics post-match, after Bayern boss Carlo Ancelotti, Vidal and Arjen Robben claimed they were robbed at the Santiago Bernabeu and called for video assistant referees.