( CNN ) -- An Illinois man is suing the Vatican and Pope Benedict XVI for allegedly covering up sexual abuse by a priest at a Catholic school in Wisconsin . The lawsuit demands the Vatican release the names of thousands of Catholic priests that the suit says have `` credible allegations of sexual misconduct '' against them . The alleged victim , who is now an adult , says he was molested by Father Lawrence Murphy while a student at St. John 's School for the Deaf , according to the complaint filed in U.S. District Court in Milwaukee , Wisconsin . `` The defendant , [ the ] Holy See , has known about the widespread problem of childhood sexual abuse committed by its clergy for centuries , but has covered up that abuse and thereby perpetuated the abuse , '' the suit says . Federico Lombardi , a Vatican spokesman , declined to comment on the case . Pope Benedict XVI was named as a defendant because he has the ultimate authority to remove priests and because of his involvement in reviewing sex abuse cases when he was Cardinal Joseph Ratzinger , the suit says . `` There are a number of priests , brothers , and agents who defendant continued in ministry after defendant knew or suspected that those agents had molested children , '' the suit says . Suit alleges U.S. , Mexican cardinals covered up abuse . Peter Isely , a director with the Survivors Network of those Abused by Priests ( SNAP ) , estimated the Vatican is investigating 4,000 cases of sex abuse by church employees . The lawsuit aims to change church policies and practices that conceal sex offenders , Isely said . `` It 's going to protect children , we hope , around the world , '' he said , `` This is a historic day and hopefully this is going to result in historic changes . '' Arthur Budzinski , a deaf man who said he was sexually assaulted and raped by Murphy , stood with Isely at a news conference Thursday . He said the priest `` may have stolen our bodies , '' but higher clerics such as cardinals , archbishops and the pope `` stole our voices . '' He made his comments in sign language and his daughter , Gigi , interpreted his words . The now-deceased Murphy is believed to have molested up to 200 boys , Isely said . The lawsuit said the church `` knew that there was a high probability that these clerics would sexually molest more children , but sought to protect itself from scandal , sought to keep its income stream going , at the peril of children . '' Murphy , it says , was a `` top fundraiser and recruiter '' for the church and the `` Holy See wanted to retain Murphy 's services . '' The same Minnesota law firm representing the Illinois plaintiff also filed suit Wednesday on behalf of a Mexican resident who says he was sexually abused by a priest . The suit alleges Catholic officials in Los Angeles , California , aided and abetted the abuse by moving the priest to different dioceses as allegations piled up against him . CNN 's Tom Cohen contributed to this report .
NEW : Priest , now deceased , is believed to have molested up to 200 children , the advocate says . It alleges a cover - up involving the priest at a Catholic parochial school . Pope Benedict XVI is named in suit that alleges cover - up of sexual abuse . The lawsuit demands the Vatican release the names of thousands of Catholic victims .