The singer and fiancé Liam Hemsworth were apparently at Beacher's Madhouse in Los Angeles on Saturday (September 8) when an altercation broke out with another patron.
Hemsworth is said to have become angry when another patron bumped into his chair, reports TMZ
Cyrus is thought to have stepped between the two men to break up the issue, but also allegedly pushed and struck the other patron.
The Los Angeles Police Department have since confirmed no arrests were made at the time, but the patron allegedly shoved by Cyrus later filed a police report.
LAPD officer Rosario Herrera told The New York Daily News: "Miley, her boyfriend and the victim were talking and an argument ensued. Miley pushed the victim and struck the victim in the face.
"There were no visible injuries and no arrests made. The victim came to the station (to file the report). It's an ongoing investigation."
Cyrus's spokesperson has reacted by insisting that all claims against the singer are "false and erroneous".
This incident came on the same day as a man was arrested on two misdemeanor counts for allegedly trespassing at Cyrus's home.