Global charity Open Doors has disputed the way in which statistics on Christian “martyrs” are collected, arguing that an annual figure of 90,000, recently reported widely, is significantly higher than the accurately verifiable number.

The figure, reported by some media and cited by an Italian academic on Vatican Radio, was published in research by the US-based Center for the Study of Global Christianity (CSGC) at Gordon-Conwell Seminary late last month. Academics said they arrived at the figure by counting estimated killings of Christians between 2006 and 2015 and dividing the total by 10.

Dr. Ron Boyd-MacMillan, director of research at Open Doors, told BBC World Service’s More or Less programme that there was “a lot of exaggeration” of figures relating to the persecution of Christians, and his team’s research showed that the number of Christians known to have been killed “for faith-related reasons” between 1 November 2015 and 31 October 2016 was less than two per cent of CSGC’s figure: 1,207.

This lower figure was found as part of Open Doors’ research for its 2017 World Watch List, which ranks the 50 countries in which it is most difficult to live as a Christian.

He added that Open Doors’ figure relied where possible on witnesses and was “probably lower than it should be, but you’ve got to give figures you can absolutely verify”.

He also told the programme, broadcast this week, that a significant fall in the number of Christians killed for their faith – from more than 7,000 during 2015 – was the result of Boko Haram jihadists in Nigeria being routed, and of Christians in Iraq and Syria having already “largely fled” the areas from which they were at risk of being killed.

Dr. Boyd-MacMillan argued that to measure “persecution”, it’s necessary to look at other indicators, such as freedom to change one’s religion to Christianity, or ease of church-building.

Gina Zurlo, the CSGC’s assistant director, explained that the Massachusetts-based centre would count anyone who “died prematurely, acting out their faith”, including Christians killed in war. Their data assumed that most Christians would not wish to take part in warfare, so any Christians who died would have been targeted for their faith. Ms Zurlo admitted that of the 90,000 cited, two-thirds had died in tribal conflicts, and nearly half were victims of the civil war in the Democratic Republic of the Congo.

Germany-based Professor Thomas Schirrmacher, president of the International Council of the International Society for Human Rights, said the figure of 90,000 was misleading because it gave “the impression that somebody counted 90,000 cases” and did not note whether the Christian who died was killed because of their faith.

However, he said higher figures served to remind people of the gravity of the problem, and added that accurate statistics did not exist. He estimated that the total number of Christians killed for their faith in recent years was less than 10,000 annually.