Oliveira inked a five-year contract with Milan for an undisclosed fee.

But the six-time European champions said in a statement that Swiss international midfielder Johann Vogel had joined Betis as part of the deal.

Milan have been in the market for a top-striker to replace Andriy Shevchenko who joined Chelsea earlier this summer.

The 26-year-old scored 30 goals for Betis since joining them from Valencia in 2004.

He was also a member of Valencia's squad that won the won the Primera Liga title and the UEFA Cup in 2004 under coach Rafael Benitez.