The number of people who died because of the Covid-19 pandemic may be three times higher than the official death toll, according to a new study that puts the total number of deaths worldwide at 18mn.

The study, which points to a vast undercount of the number of deaths, is published on the second anniversary of the World Health Organization declaring the outbreak a pandemic. The number of Covid-19 deaths reported by governments totals 5.9mn for 2020 and 2021 combined.

The paper argues that lack of access to Covid-19 tests, patchy records of causes of death, and in some countries, political incentives to undercount, all hindered an accurate count of deaths directly from the disease. The study recognised the population who died from other causes related to the pandemic, such as delays to healthcare for other conditions, unlike official figures.