You could use a liner. Get a nice big hob attach him to a harness and line, enter him into the hole where you last seen your jill, he will go down find the jill and push her off her kill (the dead bunny). The jill will come out while the hob starts munching away at the bunny, it just a case of either digging along the line or if you knew how much line as gone to ground eg. 6 feet then you can dig down to it.
I have tryed this method as i aint got a locator, but it can be a bit of a pain in the arse. This season im getting a mk III locator. Hope this helps.
HAPPY HUNTING
RS