A royal commission has heard Jehovah's Witnesses elders knew of more than 1000 cases of child abuse since 1950, but never reported them to police.

Jehovah's Witnesses destroyed notes about child sexual abuse to stop them falling into the wrong hands and to "protect their wives", a church elder has told a national hearing in Sydney.

The opening day of a royal commission hearing into abuse within the controversial church has heard how more than 1000 cases of child abuse since 1950 were dealt with internally and never reported to police.

It has also heard that victims were made to confront their abusers and left feeling as if they had sinned.

Max Horley was an elder for the Jehovah's Witness congregation in Narrogin, Western Australia, in the late 1980s when a woman, known as BCB, was interviewed about her relationship with another church elder, Bill Neill.

In evidence on Monday, BCB told how Neill, who is dead, groomed her from the age of 15. He would tongue kiss her and spy on her when she was in the shower at his home.

When the abuse was revealed, she was asked to attend meetings where on one occasion the abuser joked about what he had done.

Commission chair Peter McClellan asked Mr Horley if he had taken notes of his conversations with BCB.

Mr Horley said he may have but did not have them now, and they would probably have been destroyed.

"We do not like to keep any notes outside of what is kept on file in the congregation," Mr Horley said.

He said the file notes were brief, and they and others were destroyed because they did not want them to "fall into the wrong hands".

Justice McClellan: "What are the wrong hands?"

"Well, we do not want our wives knowing our stuff - what sort of things we are dealing with," Mr Horley said.

He also said they destroyed notes because they wanted to limit the number of people in the congregation who knew about the abuse.

When pressed on why this was done, Mr Horley said: "Just to protect them, I guess."

He said it was not the church's practice to report serious allegations of sexual abuse to police.

The elders would go for advice to the branch if they had any hesitation about how to proceed "legally and scripturally".

Mr Horley said he thought they would advise the person who was making the allegation to go to police if they wished.

BCB, who is now 47, told the commission she was never advised to go to police, the purpose of the several meetings with elders was never explained to her, and she was never offered any support.

On one occasion, her husband was warned by another elder about dragging the church's name through the mud.