The Germany international is under contract at the Emirates Stadium until June 2016 after joining the Gunners from Cologne last summer.
Prior to his move to England, the 28-year-old had spent his entire career playing in his homeland and speculation has emerged of a possible return.
But Heldt told BILD: "I am unable to make any statement on this rumour at this point in time."
Meanwhile, Arsene Wenger remains confident Arsenal will tie up deals for new players before the transfer window closes in 10 days.
"Yes, I'm confident that we'll make the signings we need because of the desire of the players to join us," said the Arsenal manager.
"There's also the fact that while we maybe don't have as much money as everybody writes, we have some funds available to do transfers.
"We've worked on it very hard but it hasn't come off as quickly and as well as we wanted.
"You'd be surprised how early we acted. In our job, you can spend a lot of time, not going on holiday and work on things without it coming off.
"In football, you have to deal with any situation and be patient. As long as the window is open, anything can happen until the last minute."