Special thanks to caver Boris Hysek for translating this information from Czech sources and providing the following report:
On Saturday 11-10-2005, cave diver Jan Sirotka from ZO CSS 6 - 25 Pusty Zleb made a connection between the cave system Amaterska jeskyne (Amateurs cave) - Punkevni jeskyne (total length approximately 30 kilometers) and cave system Sloupsko - Sosuvske jeskyne (total length approximately 6 kilometers). Cavers from Pusty Zleb Grotto have been pumping sumps between two systems for seven days, lowering the water level in the underground river by more than six meters. But, the powerful pumps failed to open the way so the connection had to be made by a cave diver who defeated the difficult chain of sumps.
Now, the biggest cave system in Czech Republic is longer by six kilometers.