Cardinal George Pell's private secretary has sent an email to colleagues in Rome asking for them to attend a royal commission hearing beginning at 10pm (local time) on Sunday in Europe.

A copy of the email, seen by the ABC, was sent out to Fathers and Seminarians saying Cardinal Pell would be pleased if they could provide support with their presence at the hotel.

It tells them to register with the Royal Commission.

The note appears to come from Cardinal Pell's private secretary, Father Mark Withoos.

Father Withoos confirmed he sent a private email to priest friends of the Cardinal who had made inquires about how they might help when he gave his video evidence.

The email has now been seen by several seminarians, clergymen and media representations, and the ABC is aware that there have been conversations with Father Withoos about gathering support.

The email says there will be at least 15 victims and advocates from Australia, and possibly others who might arrive from elsewhere in Europe, as well as a large media "cohort".

The details of the timing of the hearing are included, although the email mistakenly says it lasts from 10pm until 2pm with a half hour break.

Instead the appearance by Cardinal Pell will finish at 2am (local time).

It will resume on Monday and Tuesday night, with a possibility of a fourth night.

"Your physical attendance at any of these I know would be very much welcomed by the Cardinal," the email reads.

"All that said, the most important contribution we can all make is our prayers for him."

It finishes with Father Withoos' address and phone number.