Justin Timberlake has teased he is working on new music.

The 36-year-old singer and songwriter has hinted he is back in the studio recording hit tracks, after he posted a cryptic post on social media on Thursday (08.06.17), which saw him discuss studio etiquette and slam people who ignore artists playing their music to them as they are glued to their phones instead.

The dark-haired hunk tweeted: ''Studio Rule #1: If the artist plays their music and you are on your phone looking at your social media... Chances are, you're an A*SHOLE. (sic).''

The 'Cry Me A River' hitmaker followed up his post with another comment to laugh off his previous message.

He added: ''Just a thought. (sic)'' alongside a string of crying with laughter emojis.

Meanwhile, Justin - who has two-year-old son Silas with his wife Jessica Biel - has admitted writing his last song 'Can't Stop The Feeling' for the 'Trolls' movie was one of the hardest things he has ever had to do.

Although the American heartthrob has gone on to receive an Oscar nomination for the track, he was originally worried that he and co-writers Max Martin and Karl Johan Schuster would not be able to pen a record that would work for the animated characters to sing.

Speaking previously about his concerns, Justin said: ''This has to work for the moment, these characters, and be film. It took a second to crack the code. I remember thinking, 'We're not gonna be able to do this.'

''This wasn't just like writing a song for a movie - it was writing a song for characters that are going to sing it in the movie.

''That part had to work, and that's the part that made it a task that none of us had ever done. And we had to push ourselves to do something that works in that way.''