AC Milan may have to foot the bill for repairs after graffiti was scrawled on a wall inside the Juventus Stadium following their 2-1 defeat to the Bianconeri on Friday night, reports La Gazzetta dello Sport.

The Rossoneri were beaten by a 97th-minute Paulo Dybala penalty and somebody within their dressing room let their anger get the better of them.

According to La Gazzetta, the word ladri (thieves) was written across two plaques which line the wall heading into the Milan dressing room from the pitch. The plaques commemorated the 2005 and 2006 Serie A titles, which have officially been taken from Juve due to the Calciopoli scandal.

The report said that the choice of those two plaques might not be casual. The controversial late penalty denied Milan a point in Turin.

Napoli fans held aloft a banner ironically saying "It's a penalty for Juve!" whenever the referee blew his whistle during their 3-0 win over Crotone on Sunday, and their president Aurelio De Laurentiis said that gesture summed up the general feeling in Italian footballthat the defending champions have been on the receiving end of refereeing favours.

"There are banners which put things in a much clearer way than I could," De Laurentiis said, sidestepping a question as to whether his side can still win the title this season. "It's going to be important to see technology applied in football."

Juve's win kept them eight points clear of Roma at the top of Serie A, with Napoli two points further behind in third.

Massimiliano Allegri's men also extended their winning streak at home to 31 Serie A fixtures last Friday, giving them confidence for the visit of Porto in the Champions League on Tuesday, with a 2-0 win from the first leg giving them further comfort.