A search has been launched for three mystery ticket-holders who each won £1.6m in the National Lottery 10th Birthday draw on 6 November.
Lottery owner Camelot said they were releasing the areas in which the winning tickets were bought in the hope of finding the winners.
They are Stroud in Gloucestershire, the Vale Royal region of Cheshire and Sandwell in the West Midlands.
The mystery ticket-holders have until 5 May 2005 to come forward.
They were among six ticket-holders who shared the £10m jackpot.
The winning numbers were 5, 17, 23, 26, 42 and 48.
Players who bought a ticket for the main Lotto draw on 6 November automatically had their lines of numbers entered into the special jackpot-only birthday draw.
A spokesman for Camelot said they are still hopeful that the winners will come forward.
"The champagne is on ice and all we need now are the names to put on those cheques."