Colm O'Gorman, executive director of Amnesty International Ireland and founder of the victim support group One in Four, said it was up to the Catholic hierarchy in England and Wales to "name the truth of past failures and wilful negligence" in the Vatican's response to survivors of abuse and paedophile priests.
He made the comments as the National Catholic Safeguarding Commission, set up by the church in England and Wales 2008, published its annual report.
It said the Vatican and the British government had "singled out" the NCSC for its approach to child protection but that there was no room for complacency. It also said there would be more attention on those who had been affected by abuse.
"Recent events concerning inquiry reports in Ireland and allegations in Europe have caused distress to many. This has further emphasised the need to improve the way we respond to survivors."
It was working with insurers to agree ways in which the church could respond "sensitively and in a timely fashion" in providing pastoral care to abuse victims without compromising its insurance indemnity.
"If someone is entitled to damages for any injury or hurt caused, we must ensure that no action on the part of the church prevents them from obtaining any such entitlement".
O'Gorman, who experienced clerical abuse as a teenager in County Wexford, Ireland, and won damages of more than £250,000 from the diocese of Fearns, appeared as a panellist at the NCSC annual conference earlier this year.
He told the Guardian he was impressed and encouraged by the delegates' "palpable desire" to "do the right thing", but that the Catholic church of England and Wales could not "exist in a silo".
"It is understandable on one level that, having taken on this challenge to change from within, people might be inclined to think locally.
"But that is a betrayal of collective responsibility. If they believe the process they have undertaken is right, it needs to go beyond national boundaries."
Taking this stance would involve speaking out against the Vatican when it connected child sex abuse with homosexuality, for example, or attacked the media for reporting crimes and cover-ups.
"The Vatican has been wilfully deceitful in things it has said," he added.
It is rare for a local church to openly criticise Rome. But, last April, the bishops of England and Wales distanced themselves from remarks made by a senior Vatican official who appeared to link homosexuality with paedophilia.
A statement from the Rev Fr Marcus Stock, general secretary to the Catholic Bishops' Conference of England and Wales, said there was no empirical data to support a conclusion that paedophilia had anything to do with homosexuality.
His statement bore the authority and approval of all 32 Catholic bishops in England and Wales.
SIC: TGUK