Martin sparked rumours of a new romance when he was spotted with Chung in New York barely two months after the breakdown of his 10-year-old marriage to Gwyneth Paltrow, reported Us magazine.
Coldplay frontman's representative said such stories were "completely untrue."
Martin, 37, last spoke out about the split in an interview with BBC Radio 1's Zane Lowe, where he admitted his own issues contributed to the breakup.
"This was more a realization about trying to grow up basically... If you can't open yourself up, you can't appreciate the wonder inside. So you can be with someone very wonderful, but because of your own issues you cannot let that be celebrated in the right way," Martin had said.