Unesco gave Tiwanaku world heritage status in 2000
Bolivia's culture minister has denied that restoration work on an ancient pyramid might see it lose its Unesco World Heritage Site designation.
Pablo Groux told the BBC the government had halted the work at the Akapana pyramid in Tiwanaku earlier this year, after it was told to do so by Unesco.
Local archaeologists used a clay-based plaster, adobe, instead of stone on the structure, sparking worldwide outrage.
Some experts said they were concerned the work could even cause its collapse.
The Akapana pyramid is one of the biggest and oldest pre-Hispanic constructions in South America.
It had great spiritual significance for the Tiwanaku civilisation, which predated the Inca empire.
Archaeologists believe it was built about 2,500 years ago.
Jose Luis Paz, who was appointed in June to assess damage to the site, said the Bolivian state National Archaeology Union (Unar) had made a serious error in choosing to rebuild the pyramid using adobe when it was clearly built of stone.
"They decided to go free-hand with the [new] design... There are no studies showing that the walls really looked like this," he told the Reuters news agency.
Mr Paz said the local authorities in Tiwanaku had simply asked Unar to make the pyramid "more attractive for tourists".
He also warned that the lower decks of the pyramid were now slightly tilted because of the extra weight of the adobe walls, which could lead to its eventual collapse.
But Mr Groux defended Unar, saying that as a result of the restoration work, the structure now looked like it had done originally.
The minister also said Unesco was unlikely to drop Tiwanaku from its world heritage list because it had not been excessively altered.