Mr Castle said there was a lot of paperwork to get through before Collins' body could be repatriated.
He was avoiding any speculation on how long the lengthy formal process would take, Mr Castle said.
France-based All Blacks Neemia Tialata and Chris Masoe had dressed Collins for his journey home, he said.
"It was very comforting to the family. It's like the boys were their representatives with Jerry getting him ready for the journey home. It meant they could kind of reach out through them to their son.
"It brings them even closer to him, even though they would obviously like to be closer still."
No funeral arrangements could be finalised before the repatriation was organised, Mr Castle said.
The family would be taking the significant public interest into account with any decisions they made, he said.
"The family will of course do a number of things privately but they're very aware and very grateful for the support and sympathy and very public expressions of affection for their son.
"That's figuring in with their considerations."
A Ministry of Foreign Affairs and Trade spokeswoman said a New Zealand Embassy representative had travelled from Paris to Montpellier to facilitate the repatriation of Jerry Collins' body.
The ministry would not be providing any further information out of respect for the family's wish for privacy, she said.
NZME.