LONDON (AFP) -- Nick Kyrgios has revealed his gratitude to Andy Murray for spotting signs of self-harming as the Australian tennis star said he had an "addiction of pain" during a "dark" time in his life.

Kyrgios has opened up about the mental health struggles he suffered in recent years and revealed in a Netflix documentary he had spent time in a psychiatric hospital after losing at Wimbledon in 2019.

Three-time Grand Slam champion Murray has consistently been a supporter of Kyrgios, despite the latter being dogged by a series of on and off-court controversies,

Last year Kyrgios' mother revealed how Murray had spotted the signs of her son self-harming before she did.

“Andy was always a big supporter of me,” Kyrgios told TalkTV in an interview with Piers Morgan.

"As soon as I came on the tour, he kind of saw a work in progress and took me under his wing. Then he realised later in my career that I don’t think I was coachable or I was on my own path, but he was always someone that was looking out for me.

"He saw it (the self-harm) and he said, ‘What’s that on your arm?’ It was pretty bad at that stage. I'd be in the locker room and people would be able to see my self-harm. So I could only imagine what people would think when they were actually versing me on the tennis court. They're like, ‘Wow, this guy's mentally in a storm at the moment and he's still trying to play’.

"Andy obviously was trying to give me advice on it. But I was just so stuck in my ways at that time that I didn’t listen. Obviously I’m very thankful. I thank him a lot."

Kyrgios went on to describe the extent of his self-harming, even while playing successfully on the ATP Tour.

"I think it was a year-and-a-half to two years of just complete harm. It was pretty dark to be honest," he added.

"I won tournaments on the professional tour, drinking every night, self-harming, burning things on my arm, cutting myself for fun. It became an addiction of pain. I hated myself. I hated waking up and being Nick Kyrgios."

Since going public about his mental health struggles, Kyrgios has been contacted by others suffering similar situations through social media and described his role in helping them as the "most powerful thing" he has done in his career.

"That’s been the most powerful thing in my career; people coming to me with genuine issues," said the 2022 Wimbledon finalist.

"They send me photos in my Instagram, direct messages, self-harming and genuinely wanting to commit suicide. I have conversations with these people. Sometimes I’ve had phone calls with these people. That’s making a real difference and I’m just really proud."