SANTIAGO, Chile — Chile's latest census should be scrapped and repeated in 2015, because there was a substantial undercount of the population, an independent commission of experts said Wednesday.

The government had boasted that the 2012 census was the most comprehensive in the country's history. But after a three-month evaluation, six outside experts said it shouldn't be used to calculate official numbers.

"The commission believes that the 2012 census suffers from serious problems," the experts said in a report commissioned by the National Statistics Institute.

The report said 9.3 percent of the population was not included in the census. "That percentage is three times higher than other censuses carried out recently in other regional countries," it said.

Government officials said they welcomed the study, but made no commitment to repeat the census. Juan Eduardo Coeymans, head of the statistics institute, said that idea "is very drastic," referring to it as a "tsunami."

Chile's reputation for providing some of the most solid official statistics in Latin America has been hit by questions surrounding the gathering of the census data. The commission said the government surveyed 15.8 million people, when it should be closer to 17.4 million.

"This is a solid projection, and therefore valid to estimate the census omission," it said.

A third of those missing from the census findings were not counted because they were not at home, and two-thirds were not surveyed or were wrongfully marked as empty homes, the report said.

Experts said the census was carried out amid a climate of "strong internal divisions" inside the National Statistics Institute. Francisco Labbe, who ran the institute, resigned in April after he was accused of tweaking the census numbers and under-reporting inflation.

The commission blamed the census fiasco on President Sebastian Pinera's government but also said that problems during former President Michelle Bachelet's 2006-10 administration delayed the 2012 census.

Experts recommended that a new census with fewer questions be carried out during a national holiday.

Pinera met with some of his top aides Wednesday afternoon to discuss the report. Economy Minister Felix de Vicente said the government "shares the commission's recommendation of strengthening" the statistics institute and officials have contacted statistics experts at international organizations to "make sure the census is certain and reliable."

The 2012 census cost about $32 million, said Mariana Alcerreca, a former senior officer at the national institute who had reported the irregularities in compiling the data.