AC Milan vice-president Adriano Galliani has claimed that a potential deal for Real Madrid playmaker Kaka has hit a stumbling block.

The 30-year-old, who has dropped down the rankings at the Spanish club, has attracted the interest of his former Italian outfit.

However, Galliani has admitted that a deal may not come to pass as reports claim that the Spanish champions are requesting up to £40m for his services.

"It is very difficult," Galliani told Sky Sports Italia. "The negotiations are all to be done. There are a thousand difficulties that could well make it impossible.

"As always, the problem is money. Milan cannot afford some wages, especially as in Spain they have a different fiscal structure.

"The law there has changed for future wages but the contracts that were already signed are still valid under the old tax code."

Kaka has been at the Bernabeu since 2009.