In a statement for the Haitian daily Le Nouvelliste, Denis said he firmly rejected the accusations of murder against him, which he said were intended to tarnish his name and sow confusion, and called for an impartial investigation.
Denis said he met Christian Emmanuel Sanon, a prime suspect in the case, during an anti-president protest in Port-au-Prince in March. They briefly talked about politics and Sanon mentioned his presidential ambitions, which Denis said were "detached from the political reality."
"I have never had any other contacts with this person whom I had never heard of before or after this brief meeting in March," he wrote.
Port-au-Prince state attorney Claude Bed-Ford has issued arrest warrants for Denis and four others in connection with the killing. Haitian police arrested 26 Colombians who allegedly stormed the president's residence on July 7, shooting him dead and wounding his wife.