Justin Bieber has apologised to Marilyn Manson over their t-shirt design feud.

The 23-year-old singer reportedly claimed he made the 'Beautiful People' rocker ''relevant'' again after using an image of the star without his consent in his 'Purpose World Tour' merchandise in 2016.

Marilyn later fired back, calling the 'Sorry' hitmaker ''a piece of s**t'', but now it seems they've put their differences aside as the controversial rocker has revealed Justin has apologised for being ''an a**hole''.

Justin told Marilyn - real name Brian Warner - over text message: ''I thought we had a pretty pleasant interaction. Also, if anything wasn't squared away with the T-shirts, I'm so sorry. Anyway, regardless, it kind of stung seeing that I came off as an a**hole or even just was an a**hole, I'm sorry?

''Honestly, I totally thought we hit it off. Again, my bad. If I was an a**hole, that wasn't my intention. Just want you to know that. I don't really care about the media. I just wanted to make sure you and I were good because I like you.''

The 'Sweet Dreams' singer, 48, read the text messages out during his appearance on 'The Howard Stern Show' on Tuesday (19.09.17), and read out his response in which he too agreed to settle their feud and said the pair were ''cool''.

Marilyn wrote back: ''We are cool. People just made that shirt stuff into a fake feud. Let's turn it upside down and f**k the press and do something together. It will be the best. And don't apologise. You weren't an a**hole. They asked if you were and I sort of agreed. I wasn't out to get you. If not, I'll try to avoid more questions today on Stern.''

Originally, Marilyn claimed the 'Love Yourself' singer had made a ''bad mistake'' in confronting him about the t-shirt design, and branded him as ''arrogant''.

He said: ''He was [already] wearing the shirt that had his name on my shirt, and he said to me, 'I made you relevant again.' Bad mistake to say to me. He was a real piece of sh*t in the way he had the arrogance to say that. He was a real touchy-feely guy, too, like, 'yo yo bro!' and touches you when he's talking. I'm like, 'you need to stand down, you're d**k height on me, ok?' Alright? So stand down son.'

''The next day I told him I'd be at his soundcheck at Staples Center to do 'Beautiful People'.''