Five Americans who were sexually molested by Catholic priests will sue the Vatican to get the names and details of priests involved in abuse, an attorney for the group said on Monday.
The lawsuit in US federal court, which will be formally announced in the city of St Paul, Minnesota on Tuesday, aims to compel the Vatican to open its archives and "release all the identities of thousands of offenders known exclusively by the Vatican and held in strict secrecy," lawyer Jeff Anderson said in a statement.
The petition also asks for the offenders' "files and pertinent histories".
The lawsuit comes after Pope Francis announced this month that every Catholic diocese would have to come up with a plan for reporting abuse.
The measure was expected to bring countless new cases of molestation to light. But it has not satisfied victims' groups because it doesn't compel reporting of abuses made in confession nor does it force dioceses to tell authorities when abuses are reported.
The Vatican is struggling to deal with a global epidemic of sexual assault by priests, in particular of minors. Much of the abuse has gone on for decades.
A grand jury investigation into dioceses in Pennsylvania published in 2018 threw light on sexual abuse systematically covered up by the Church by "over three hundred predator priests", with more than 1 000 child victims identifiable.
Between 1950 and 2013 the US Catholic Church received 17 000 complaints of sexual abuse said to have taken place from 1950 to 1980 involving around 6 400 clerics.
Experts speaking at the Vatican said in 2012 the number of abused American minors is probably close to 100 000.
Several senior church members in the US have been forced to resign for protecting pedophile priests, including the late cardinal Bernard Law.