Two of Glen Campbell's children are launching a legal battle against the ailing country star's wife, Kim.

The Rhinestone Cowboy singer, who resides in a full-time care facility as he battles Alzheimer's disease, is allegedly "secluded from the rest of the family" at Kim's hands.

His eldest children, Debby Campbell-Cloyd and Travis Campbell, have lodged a petition at a court in Nashville, Tennessee, accusing the singer's wife of prohibiting them "from participating in his care and/or treatment".

They are urging a judge to appoint conservators and a guardian to protect their father's medical and financial interests.

Campbell-Cloyd has previously protested against Kim's decision to move her father to the facility, to which Kim responded, "It is crushingly sad to see him afflicted with Alzheimer's but indulging those feelings does not help him. I am his wife and no one wants him home more than me but I must do what is in his best interest."

The singer has been married to Kim since 1982 and shares three of his eight children with her. Campbell-Cloyd is from his first marriage to Diane Kirk, and Travis Campbell is from his second union, with Billie Jean Nunley.