A debate over the reliability of coronavirus data has been taking place almost since the beginning of the outbreak and extends from China to the United States. Many countries have not tested enough people to track infections, let alone establish how many deaths have been caused by the virus.

But the debate is taking place with singular ferocity in Spain.

The far-right political party Vox has pushed the cover-up accusations hardest. Last week, it posted on social media a manipulated photo of Madrid’s Gran Vía thoroughfare filled with coffins draped in Spanish flags. The government, Vox claimed, was hiding “the suffering of this tragedy.”

Helena Legido-Quigley, an associate professor of public health at the University of Singapore, said there were many reasons that the authorities worldwide should improve the counting of their dead. One is the brutal nature of the pandemic. Untold numbers of people have been forced to remain apart from loved ones as they died — and then unable to hold proper funerals for them.

“We know how important death rituals are in Spain and so many other countries,” Ms. Legido-Quigley said. “So the authorities should help reduce the huge impact on a society of having now been forced to dehumanize the process of dying.”

It is not just a matter of lacking testing capability. The problems of counting the dead are also compounded because not all nations have followed the same methodology.

In France, for instance, the counting was changed in early April to add nursing home deaths, which raised the toll by more than 3,000.