He believed his brother was guilty of the murders and said he felt vulnerable when publicity around the case increased.
"It does make it difficult because you don't know what's going to happen. It's just fearful for what's going to happen around the corner and how are we going to get through with the things with the kids, with their vulnerability."
He believed Mark was guilty because of what people had said to him and "what I know of him, what he is just as a brother".
"It's not going to change anything, he's still my brother, I still love him as a brother, but there's a difference between head and heart."
He did not know what grounds Lundy would be appealing on, nor did he know anything about how it would be funded.
A spokesman for Mark Lundy support group Factual (For Amber and Christine - Truth Uncovered about Lundys) said a new appeal was lodged with the the judicial committee of the Privy Council in London on Monday.
Lundy would be represented by lawyer David Hislop QC, a New Zealander who now works in the UK.
Factual was largely funding the appeal, the spokesman said.
"Most of it's pro bono really. We've had a lot of people work pro bono and all of the scientists worked free of charge."
Should it go ahead, the appeal could be one of the last of its kind - the Supreme Court replaced the Privy Council as New Zealand's highest court in 2004.
According to the Supreme Court Act, 2003, the Privy Council can still determine appeals in certain existing proceedings, including appeals against Court of Appeal judgements made before January 1, 2004.