A massive stash of what was believed to be uranium found in Bolivia's capital contains just 68 grams of the radioactive material, Bolivia's Interior Minister said.
The quantity is too small to put people's health at risk, Carlos Romero told reporters.
"The laboratory report indicates that there is uranium, but in small amounts. An approximate calculation (shows there were) only 34 grams (one ounce) per ton, or 68 grams in the two tons" of material found, he said.
An investigation is still ongoing to determine the origin and intended use of the mineral.
Last week, Deputy Interior Minister Jorge Perez said the "radioactive" uranium had been discovered in bags at a garage on the ground floor of a building in central La Paz, not far from the US and Brazilian embassies.
A few hours later, his boss indicated that the nature of the material had not been determined.
Bolivia's state-run mining company Comibol subsequently said the find was not uranium but likely tantalum, a metal used to make electronics equipment.
Four people were detained and then released in the investigation that followed.