At the beginning of December 2005 twoSlovenian cavers visited the entrance of BC–4and reached a depth of 70m. Later the initiatorand leader of this action, Slovenian freelancecaver Rok Stopar, accompanied by severalItalian cavers from Gruppo Grotte Brescia,reached a depth of 200m on a 16–hour trip.Subsequently different groups of Italian andSlovenian cavers enlarged the narrow sections,finally reaching –650m.
On December 10 an Italian group passedthrough a tight squeeze at –700m anddescended a further 200m in depth and along400m of horizontal passage, entering theMillennium series in Mala Boka Cave. Theyreturned to the surface after 20 hours. On theDecember 17 and 18 a group of four Slovenianand four Italian cavers descended BC–4 andmade a through trip to MalaBoka Cave in 24 hours.Joze Pirnat, the Sloveniancaver who was in charge ofcoordinating internationalexploration efforts in theKanin massif in the years1997–2001, sent a letter tothe Poles expressing hispoint of view on these events.He states that the Polishcavers were undoubtedlyentitled to find the fifth cavein the Kanin deeper than 1,000m. The expectedconnection of BC–4 with Mala Boka Cave in thesummer of 2006 would be a certainty for the nextPolish expedition. Unfortunately some of theSlovenian–Italian team that for the last four yearshad been exploring Mala Boka Cave, decidedto subvert the Polish achievement and pushedBC–4 regardless of good manners and rules offair play. Slovenian cavers and other explorersof Kanin were informed after the event that theconnection had been made. Even with the bestof intentions, such as extending the explorationseason in Mala Boka Cave (which was accessibleonly in winter) and making exploration inMala Boka Cave safer, one cannot excuse thebehaviour of the Slovenian / Italian team.