"They've been dating for a few weeks," the source says.
Tran's rep, however, says the two are not dating and that the model is single.
The two stepped out for the KURIOS - Cabinet of Curiosities Cirque du Soleil show Friday night in Los Angeles. They later went to The Nice Guy in West Hollywood, where Justin Bieber gave an impromptu performance on the piano.
Tran dated Brown on and off from 2011 until earlier this year. She called it quits for good in March 2015 after learning that the 26-year-old rapper fathered a child with another model, Nia Guzman.
Upon hearing the news, Tran tweeted, "Listen. One can only take so much. The best of luck to Chris and his family. No baby drama for me."
The L.A. native also made headlines for her rumored romance with Rob Kardashian, who shared (but later deleted) a screen grab from a text message Tran sent him in September.
Morten, 33, is a DJ and producer originally from Aarhud, Denmark. He now lives in Los Angeles, where Tran also resides.
Back in March, Tran sat down with spiritual life coach Iyanla Vanzant for an OWN television event, where she shared her thoughts on Brown and the love triangle between her and another of Brown's ex-girlfriends, Rihanna.