AJ McLean has remembered Liam Payne as an "incredible human being".
The former One Direction star died in October, aged 31, and AJ has now lavished praise on the singer after working with Liam on the Netflix show 'Building the Band'.
The Backstreet Boys star, 46, told E! News: "He was an incredible human being. He was such a talent and such a bright light."
Liam struggled with substance abuse during his time in the spotlight, and AJ saw some strong similarities between himself and the 'Strip That Down' hitmaker.
AJ - who has struggled with alcohol and drug addiction - shared: "I know from personal experience, when you're going through something like that, you don't really reach out to people that are sober.
"It's not because you don't want to, it's you don't want to be held accountable necessarily. So, I totally get where he was at. I've been there."
Earlier this month, Rita Ora paid a heartfelt tribute to Liam at the MTV Europe Music Awards.
The 33-year-old pop star hosted the awards show at Co-op Live in Manchester, and Rita paid a glowing tribute to Liam during the ceremony.
Rita - who collaborated with Liam on the 2018 single 'For You' - said: "I just want to take a moment to remember someone very, very dear to us. We lost him recently and he was a big part of the MTV world and my world.
"Liam Payne was one of the kindest people that I knew."
Rita also observed that Liam "left such a mark on the world".
She said: "He had the biggest heart and was always the first person to offer help in any way that he could. He brought so much joy to every room he walked into and he left such a mark on the world."
