Lawyers representing former altar boys who were allegedly sexually abused by a Catholic archbishop in Guam became disheartened about their case when one of the accusers refused to testify in the Vatican’s investigation into the claims Thursday.

Roland Sondia, who publicly accused Archbishop Anthony Apuron of molesting him in the 1970’s when he was 15, reportedly said he wouldn’t share his testimony with the head investigator, American Cardinal Raymond Burke, because his attorney wasn’t allowed to be present while doing so.

Sondia’s lawyer, David Lujan, said the chances of winning the case became “worse” than he expected when he was told that he wouldn’t be allowed to advise his client during his testimony. Lujan said he feared Sondia, who was once devoutly Catholic, might be distracted from the facts of the case while he was to be “questioned by the prosecutor, who is a priest, and Archbishop Apuron’s lawyer, who is a priest, and a presider who is Cardinal Burke, and a notary who is also a priest.”

Sondia might send a written account of his testimony instead, Lujan said.

Another witness, the mother of a deceased altar boy who similarly accused Apuron of sexually abusing him, has also refused to testify in the investigation.

Because Guam is a U.S. territory, the alleged victims have also sued Apuron and the archdiocese in Guam in U.S. courts. Apuron, 71, has denied multiple claims of sexually abusing altar boys in the 1970’s and hasn’t been criminally charged.

Lujan told Radio New Zealand that there was a widespread conspiracy to “cover up” sex abuse among Catholic priests in Guam. 

“I'm dubious about anything regarding the Catholic Church and how it deals with priests and sex abuse complainants. The history has been nothing but to cover up,” Lujan said.

Cardinal Burke has been seen by traditional-leaning Catholics as a champion for their conservative agenda after being involved in high-profile clashes with Pope Francis over his progressive mercy-over-morals priority. Burke, who headed the Vatican high court until being removed by Pope Francis in 2014, called every act of abuse done by a priest a “great evil.” But Burke has come under fire from social activists for saying that clergy members who molested children did so because they were gay and “were feminized and confused about their own sexual identity.”

The Vatican revealed that 848 priests who had raped or molested children were defrocked in the 3,400 cases of abuse reported between 2004 and 2014, while 2,573 received lesser punishments, according to a report from CBS News from May 7, 2014. There were at least 410,000 Catholic priests worldwide in 2014, according to the Catholic News Service.