Reports in Germany claim Celtic are weighing up a £2million offer for the Cameroon international.
Atouba is in the final year of his contract with Hamburg, having joined the Bundesliga side in 2005 from Tottenham.
He was sold by Spurs when Martin Jol, now Hamburg coach, was in charge at White Hart Lane and Atouba could be on the move again.
The defender is aware of Celtic's standing in the game, but is unsure if there have been any detailed negotiations.
"What I know is that my contract with Hamburg will expire in 2009, so I can't say anything," Atouba told Sky Sports.
"I am under contract, it's up to the clubs.
"I have nothing to say, let me enjoy my holiday."
When asked about Celtic, he replied: "They are one of the most popular teams in the world, their stadium is fantastic and their fans are among the best."