Outspoken Irish singer Sinead O'Connor has called for Pope Benedict XVI to step down, amid reports church leaders covered up the widespread sexual abuse of children for three decades.

Just last month, allegations the Vatican had "obsessively" hidden child abuse from 1975 to 2004 were released.

The findings appeared in The Murphy Commission Report - the result of public inquiries conducted in Ireland into a sexual abuse scandal in the Dublin archdiocese.

The Vatican issued a statement on Friday, insisting the Pope felt "outrage, betrayal and shame" over the scandal and would write to the Irish people about sexual abuse.

But O'Connor believes the pontiff has remained silent about the issue for too long.

In a letter published in British newspaper the Independent, she writes, "I demand the Pope stand down for his contemptible silence on the matter and his acts of non-co-operation with the enquiry. Popes have had no problem voicing their opinions when we wanted contraception or divorce. No problem criticising The Da Vinci Code. No problem criticising Naomi Campbell for wearing a bejeweled cross.

"Yet when it comes to the evils done by paedophiles dressed as priests they are silent. It is grotesque, unbelievable, bizarre and unprecedented. They stand for nothing now but evil."

O'Connor caused uproar in 1992 by ripping up a picture of Benedict's predecessor Pope John Paul on live U.S. television.