Sinead O'Connor claims she is being detained in hospital against her will.
The 'Nothing Compares 2 U' singer - who claimed on Facebook last month she had taken an overdose but was found safe by police - says she has been ruled a "perfectly fit mother" by social services, but was ordered to receive treatment under the mental health act because she wouldn't agree to supervised access of one of her youngest children, Shane 11,
She wrote on Facebook: "So get this development. And welcome to ireland. Where it is still a crime to be a woman. Last week I get the all clear from social services. That I'm a perfectly fit mother.
"Today I get detained against my will under the mental health act by St Patrick's Hospital, and Tusla [Ireland's children and family agency] because I refused to be subjected to the humiliation of 'supervised access', as if I were ever a harm to my child.
"Two men arrive. Commence telling me what I may say or not say when I see my child. I'm to smile for example. Not to howl crying, as I am once they tell me this is not a f***ing joke. For real. I refuse.
"I say I wish to leave the hospital. I'm then given a leaflet. A f***ing leaflet! And told I'm now being detained against my will."
The 49-year-old singer went on to threaten to "smash" the hospital and anyone "even remotely responsible" for what has happened to her.
She added: "I'm ready to smash the f***ing place to pieces. and every f***er who is even remotely responsible for doing this to my son and me.
"May God forgive you because I never will. I don't care who you are, You're scum. And you're dead to me."
Sinead is locked in a battle with her eldest son Jake and Shane's father Donal Lunny over custody of the little boy and her youngest child, eight-year-old Yoshua.
She also has a 19-year-old daughter, Roisin.
Bang Showbiz