Buderus, 33, is contracted to Leeds for one more year but has expressed interest in returning to the Knights, for whom he played 220 NRL games, for a swansong campaign under incoming coach Wayne Bennett.
Leeds chief executive Gary Hetherington told the Newcastle Herald last week that there was ‘‘no dialogue’’ between the two clubs.
But a Knights source confirmed last night that there had been informal discussions this week and that the two clubs were ‘‘working through the process’’.
There is widespread speculation that Leeds are seeking a $150,000 transfer fee for the former Test rake.
Last year Canterbury paid an estimated $100,000 so the Rhinos would release Kiwi forward Greg Eastwood.