Egypt's antiquities minister denied claims that the country's first, Djoser pyramid had been damaged during restoration work by a company accused of being unqualified to do such work.
Addressing journalists who had been allowed inside the 27th century BC pyramid near Cairo, Mamdouh al-Damati said: "You have seen the inside of the pyramid. It has not been destroyed; it is not in danger."
"Restoration work is underway without a problem," the minister added in his remarks to the journalists, who had been invited to see for themselves so that they did not spread "rumours".
But Marwa al-Zeiny, a specialist in the restoration of antiquities, claimed that the company hired to do the work, Al-Shurbagy, does not have the experience for such projects, and she criticised what has already been done.
"There is an enormous visual difference between the part (of the pyramid) already restored" and the rest of the structure, she told AFP.
"The part that has been restored gives the impression of being a new pyramid, which contravenes all international norms."
Al-Shurbagy's project manager, Michel Farid Ghobrial, brushed aside the criticism, saying the work done "gives the pyramid the appearance it would have had when it was first built".
Zeiny called for the appointment of a committee of independent international experts to evaluate the work and decide whether the tomb "is in danger or not".
The tomb, built by the master architect Imhotep for the Pharoah Djoser, is located in Saqqara necropolis some 20 kilometres (12 miles) southwest of Cairo.
It consists of six mastabas, or flat rooves of rectangular structure of decreasing size. It originally stood 62 metres (203 feet) tall.
Renovation work began in 2006 but has been on hold since early 2013 due to a lack of funding.