Allens Arthur Robinson partner Malcolm Stephens, who worked pro bono on the matter with a team of Allens lawyers, said he was delighted that the legal team was able to come up trumps in the matter, especially after so much hard work.

"I thought we were able to put some strong legal arguments to the court, but I wouldn't say that I was confident that we would win," he told Lawyers Weekly.

"The team worked extremely hard to prepare this matter for hearing in a very short timeframe. I don't know how many hours were involved, but I do know that we had lawyers working on weekends and putting in many late nights."

In a six to one judgment (Justice Heydon dissenting), Chief Justice Robert French ordered that Immigration Minister Chris Bowen be restrained from sending asylum seekers to Malaysia due to the fact that the deal was made "without power and is invalid".

Stephens worked alongside refugee lawyer David Manne, as well as fellow Allens colleagues Claire Forster, Rebecca Kelton, Tom Prince, Mitch Riley, Thao Tran, Anna Payten, Edwina Watson and Clare McMurtrie.