Archeologists have clashed at a conference in Egypt over a theory that secret burial chambers could be hidden behind the walls of King Tutankhamun's tomb.

Speaking at the conference on Sunday, former antiquities minister and famed Egyptologist Zahi Hawass rejected the theory that undiscovered chambers lie behind the tomb and could contain the tomb of Queen Nefertiti, one of pharaonic Egypt's most famous figures. The theory has prompted new exploration and it has been extensively scanned by radar.

"In all my career ... I have never come across any discovery in Egypt due to radar scans," Hawass said, suggesting the technology would be better used to examine existing tombs that are known to contain sealed-off chambers.

British Egyptologist Nicolas Reeves, meanwhile, defended the theory he put forward last year. Preliminary results of successive scans suggest the tomb contains two open spaces, with signs of metal and organic matter lying behind its western and northern walls.

Foreign diplomats and Egyptologists attend the opening of an exact replica of the Tomb of Tutkankhamun in Luxor, Egypt, in 2014. In 2015, British Egyptologist Nicholas Reeves proposed, after analysis of high-definition laser scans, that Queen Nefertiti's tomb could be concealed behind wall paintings in the famed boy king's burial chamber. (Khalil Hamra/Associated Press)

"I was looking for the evidence that would tell me that my initial reading was wrong," he said. "But I didn't find any evidence to suggest that. I just found more and more indicators that there is something extra going on in Tutankhamun's tomb."

The conference aims to bring broader scientific rigour to what so far have only been tantalizing clues in recent explorations of the tomb.

Antiquities Minister Khaled el-Anani, who attended the conference, said that scans of the tomb would continue in line with the group's recommendations, but that no physical exploration would be allowed unless he was "100 per cent sure there is a cavity behind the wall."