The 19-year-old appeared to have four pink scratches on her wrist as she left her pilates class, reported Radar Online.
It is the second time in recent months that Cyrus has been spotted with similar markings on her arm.
In April, Cyrus denied reports she had self-mutilated, although she did not elaborate on what caused the apparent scrapes. That same month she was hospitalised after she caught her hand in a kitchen blender, slicing open her left index finger.
One of the markings appears to have occurred overnight, as the singer flashed that section of skin the day prior, unveiling a new tattoo.
The strange marks were in view when Cyrus showed off her new tattoo, a quote from former US president Theodore Roosevelt.
She had recently posted a picture of her new tattoo on Twitter. The quote is taken from Roosevelt's speech which he made at the the Sorbonne, Paris, on April 23rd 1910.
A spokesman for the singer is yet to comment on the issue.
