Shakhtar Donetsk have hit Real Zaragoza with a £17 million compensation demand over their signing of Brazilian midfielder Matuzalem.

The Ukrainians allege that Zaragoza colluded with Matuzalem to terminate his contract without permission after an official approach for the player was turned down.

In July, Zaragoza said they had agreed a deal with Shakhtar after bidding £8 million for the 27-year-old but the Donetsk team said they rejected the offer.

Shakhtar said they were particularly upset at losing Matuzalem on the eve of their Champions League campaign.

"The illegal approach and transfer are the fundamental causes of our complaint," Shakhtar executive director Serhiy Palkin said in a statement sent to Reuters.

"But FIFA must also take into consideration Matuzalem was a vital member of our team, someone who would be extremely difficult and expensive to replace."

A spokesman for Zaragoza said the Primera Liga club were unconcerned.

"Zaragoza aren't worried by the matter," he said. "We followed FIFA guidelines and so did the player.

"We have given FIFA our side of the story and the matter is now in their hands."