MARRIED WITHOUT A PRENUP: Hailey Baldwin and Justin Bieber. Photo: Instagram

The 24-year-old singer reportedly alarmed his team when he was spotted at a courthouse in New York with his 21-year-old model fiancée earlier this week, prompting speculation they had tied the knot, as he has not yet taken steps to protect his multi-million dollar fortune.

A source told The Sun: "Justin and Hailey arrived just after 4pm and snuck into the courthouse through a back door, there was confusion about what happened.

“They didn’t tell anyone on their teams what was going on and his people have been frantically trying to get his business affairs and finances in order."

Despite the speculation, Hailey has insisted that they have not yet wed, tweeting: "I understand where the speculation is coming from, but I’m not married yet!"

However, it has been claimed that the pair have tied the knot but don't consider themselves officially married until they hold a religious ceremony.

A source told PEOPLE: “They went ahead and did it without listening to anyone.  They’re going to have a big blowout, in front of God and everyone they love."

The pair got engaged in July, just two months after they reconciled. They first started dating in 2015.

Justin confirmed the engagement, by sharing a picture of them together and writing: "Was gonna wait a while to say anything but word travels fast, listen plain and simple Hailey I am soooo in love with everything about you! So committed to spending my life getting to know every single part of you loving you patiently and kindLY. I promise to lead our family with honor and integrity letting Jesus through his Holy Spirit guide us in everything we do and every decision we make. My heart is COMPLETELY and FULLY YOURS and I will ALWAYS put you first! You are the love of my life Hailey Baldwin and I wouldn’t want to spend it with anybody else. You make me so much better and we compliment eachother so well!! Can’t wait for the best season of life yet!. It’s funny because now with you everything seems to make sense! (sic)."