Middlesbrough are edging closer to signing Heerenveen striker Afonso Alves.

The Dutch FA have ruled that Heerenveen are not obliged to sell him to AZ Alkmaar.

The KNVB committee ruled on Wednesday that the first-option arrangement AZ thought was in place is invalid, and they will make a decision on Thursday on the pre-contract agreement the club believed they had secured with Alves.

Should they reach a similar decision, Heerenveen would be free to open negotiations with Boro, who have been on the 26-year-old Brazilian's trail for months.