The award, established in 2007 by chairman and founder of Speed and Stracey Lawyers Robin Speed, is presented each year to a person considered to have made a significant contribution to improving revenue law in Australia.

The award's namesake - former Federal Court Justice Graham Hill, who passed away in 2005 - was a recognised expert in taxation law. He made a broad and outstanding contribution to this area of the law through his work as a teacher, author, solicitor, advocate and judge.

Announcing Leslie as the winner for 2009, Federal Court Justice Richard Edmonds described her as a "titan in the field".

"Catherine's acumen, judgment, balance, industry and integrity make her a role model for all legal representatives of tax litigation," he said.

Also speaking at the ceremony was John Durack SC, who said that what impressed those consulted as part of the award selection process was the balance Leslie brings to her role.

"What impressed [them] ... was the quietly formidable way she performs, and has for many years performed, her often difficult role," he said. "She knows not just what could be argued, but what would be sensible, just and equitable to argue."

In accepting the award, Leslie her selection came as a great surprise. "I've always seen myself as just a litigator, not as a specialist and certainly not a tax specialist," she said.

Leslie explained that she never intended to specialise in tax law, and she fell into the area when she took up a part time, fill-in role at the AGS many years ago. "It ended up being a bit longer than that... it's disconcerting to think I've now been at the AGS for almost half my life," she joked.

However she said that since she's become comfortable with the area, she's never felt tempted to work anywhere else, and that she was honoured to accept the award.

- By Zoe Lyon