AceShowbiz - Representatives for Demi Lovato have warned the young star's estranged father to stop speaking out about her stint in rehab - arguing he knows "nothing" about his daughter's situation. The Disney star canceled her tour with the Jonas Brothers and checked into a treatment center at the weekend to deal with undisclosed "emotional and physical issues".

Her father, Patrick, subsequently spoke to reporters about his troubled daughter, blaming the "pressures" of fame for her problems. Patrick split from the actress/singer's mother, Dianna, in 1994 and has had little contact with the star or her sister Dallas since, and he now reveals lawyers for Disney are attempting to keep him silent about his daughter's situation.

He tells the New York Post's gossip column Page Six, "Demi won't even talk to me. I don't blame Disney (for her troubles)... Disney has been wonderful to my daughter. Now their lawyers are warning me not to say anything else. I would never blame Dianna. She is a wonderful mother. I love Demi, her sister, Dallas, and Dianna. I think about them all the time and I pray they are OK and safe."

Lovato's attorney, Jamie Young, says, "No one speaks for Demi except for her designated representatives. Unfortunately, several people have taken it upon themselves to speak out - both on and off the record - about a situation they know nothing about."