The Morocco playmaker's move from Montpellier was announced on Sunday by the Ukrainian club, whose website then featured a picture of him with his new Dynamo number 90 shirt.
L'Equipe reported this morning that the 23-year-old had had a change of heart, and also suggested he may have signed only a pre-contract agreement rather than full terms.
But Belhanda told his new club's website: "I am very glad to become a player of Dynamo Kiev.
"The day before yesterday I signed a five-year contract with the club.
"Dynamo are the top club in Europe, who I very much want to play for and with whom I dream to win the Ukrainian championship. I hope to play a key role in the team, especially in the Europa League.
"I will not comment on rumours which appeared in the French press. I can only say that I'm a Dynamo player and will represent the colours of the club in the coming years."
Belhanda was Montpellier's joint top scorer in Ligue 1 last season, with 10 goals in their failed defence of their title. His form saw him linked with English sides Arsenal and Aston Villa before he ultimately moved to Kiev.