Miley Cyrus is reportedly in a secret relationship with Mike WiLL Made It.

The 'Wrecking Ball' hitmaker, who was first linked to the music producer following her split from fiancé Liam Hemsworth in September 2013, is said to have been quietly dating him for nine months and their romance is now getting ''pretty serious''.

A source told Us Weekly ''Everybody in her circle knows they've been together this whole time.''

Another insider said that the 25-year-old producer, who worked on Miley's latest album 'Bangerz,' has also formed a close bond with Miley's mother, Tish Cyrus, adding: ''Tish says he's part of the family.''

Miley, 21, is currently on a break from her 'Bangerz World Tour' and will kick off the North American leg on August 1, but she and Mike - real name Michael Williams - make sure to ''talk and test all day, every day'' when they're apart.

An eyewitness said the duo were ''all over each other'' at the BET Awards afterparty on June 28.

The 'We Can't Stop' singer was originally thought to have only enjoyed a brief fling with Mike, as she was also spotted cosying up to a number of other men, including her assistant Cheyne Thomas, 'Twilight Saga' star Kellan Lutz and Rolling Stone photographer Theo Wenner after splitting from 'The Hunger Games' star Liam, 24, last year.