Alex Welch, 21, claims the singer-and-actress – who is currently in rehab receiving treatment for "emotional and physical issues” – lashed out on a plane after blaming the dancer for reporting her poor conduct to managers on the Jonas Brothers tour, on which the Disney star was support act.
Alex said: "To this day, I haven't gotten an apology. I've heard nothing. That's sad if you think that person is your friend."
Her attorney Donald Karpel added: "We have contacted the Lovato camp and we are waiting for a response. If we don't hear back, we will pursue litigation."
Recalling the alleged attack, Alex says it happened after Demi had been told off about her behaviour and, believing one of the dancers were responsible, the teenage star took them into a room and threatened them, saying: 'If I find out who told on me...' "
However, Alex insisted she had no idea what the star was referring to and was stunned when Demi approached her on the plane the following day and punched her.
She told People magazine: "We were on the plane with the Jonases having this awesome time and I didn't get a call or text from Demi or a, 'Hey, you got a problem with me,' nothing. And she walks up and punches me and literally walked away and got in her seat.
"No one should walk up and do that and brush it over, it's not right.”
Demi left the tour immediately after the incident and checked into rehab, with those close to her insisting her treatment schedule is the reason why she hasn’t been in touch with Alex.
A source said: "Demi hasn't been able to call Alex because she is sequestered in treatment, but multiple efforts have been made to reach out to her."
Demi’s representatives are hopeful Alex will not have to take legal action over the incident.
Her spokesperson said: "We are in the process of engaging with Alex's lawyer and hope to resolve this as quickly as possible."
