The United Nations has sent the Government a please-explain letter over the stalled police investigation into claims of child torture at the former Lake Alice psychiatric hospital.
The UN's committee against torture has raised concerns over the police decision to end its investigation in 2009 without prosecuting any staff of the now-closed hospital near Wanganui.
Ex-patients and the Citizens Commission on Human Rights - a psychiatry watchdog linked to the Church of Scientology - complained to the UN over what they consider a lack of justice for victims.
A representative of the UN committee, Felice Gaer, asks in her letter if the Government "intends to carry out an impartial investigation into the nearly 200 allegations of torture and ill-treatment against minors at Lake Alice" and prosecute and punish the perpetrators.
She asks if there will be an independent review of the "sufficiency" of the police investigation, if there will be a probe into claims the police failed to interview some complainants, and if the investigation will be re-opened.