I see from an article posted on Dr. Hawass's website
that endoscopic and robot cameras have been used to explore the "tunnel" in the northwest corner of the third level of the Osiris Shaft with interesting results:
"One interesting feature of the Osiris Shaft is a narrow tunnel that extends from the northwest corner of the lowest level. This tunnel is only large enough to admit a young child at its entrance, and further along, it becomes filled with mud. In 1999, I sent a boy into the tunnel to explore it. He was able to go only 5 meters before it became too narrow for even his slight frame. In the November of 2008, television producer Richard Reisz supplied the SCA with an endoscopic camera to continue the exploration of this small tunnel. The team who carried out this effort were able to insert the endoscope only 10 meters into the tunnel before the mud inside made it impossible to go further. In December, the team returned with two self-propelled “rovers” equipped with cameras, which were able to travel further into the tunnel. At about 6.5 meters, the team discovered a branch that split off the tunnel. They were able to send the camera 10.5 meters into this branch before it became too narrow and muddy for the rovers to go any further. The team also found that the main tunnel continues to a total length of about 21 meters, where it seems to end, although it was impossible to determine this with certainty. I have been in touch with a Japanese team who plan to bring in an even more advanced robot, which should be able to continue past the points where the earlier machines were forced to stop. On Thursday, June 9th, 2009, we will begin the work of sending the new robot into the tunnel in the hope of finding out where it leads. Hopefully, we will be able to find out why it was carved out of the rock so deep underground. Solving this mystery will truly be an amazing adventure, and I hope that you will enjoy learning the answer to the secret of the Osiris shaft along with me and my team!"
You can also download a detailed report of the discovery and excavation of the Osiris shaft by Dr. Hawass complete with plans from: