Tristan Thompson. Picture: Bang Showbiz

Tristan Thompson has called his ex-girlfriend Khloe Kardashian a "beautiful diamond" in a now-deleted Instagram comment.

The 28-year-old basketball player may have split from the "Keeping Up With the Kardashians" star - the mother of his 17-month-old daughter True - in February after he kissed Jordyn Woods but he couldn't resist making a flirty comment on her Instagram account.

Khloe shared a selfie in which the sun was behind her and captioned her Instagram post: "May you have the courage to explore every dream you dream."

In a now-deleted comment, Tristan wrote: "The sun is shining bright on a beautiful [diamond].(sic)"

His comment came a few days after the NBA star left another compliment on one of his ex-girlfriend's posts.

In a photo of Khloe "channeling Anna Nicole Smith from her Guess campaign", Tristan called it "perfection" and added a heart-eyes emoji but later deleted his comment.

The "Revenge Body" host recently admitted she was tired of receiving "countless" attention from Tristan in the wake of his kiss with Jordyn, so decided to get a therapist involved to stop any interaction between them turning sour.

In scenes aired on "Keeping Up With the Kardashians" earlier this month, the 35-year-old beauty said: "All Tristan does is sent countless amounts of flowers, calls, texts, and I just haven't been ready to talk to him because I feel like it's going to turn into a screaming match and I don't care to scream. But I said that I would be willing for the first time to speak to him if there's a therapist involved."

The former couple had their therapy session over FaceTime - although none of it was captured on camera - but it didn't go as well as Khloe had hoped.

She told her assistant: "It was a really, really hard time for me.

"I am fighting with myself now. Did I make the right choice by including Tristan in True's birthday party?"