THE number of deaths recorded in Scotland this January was the highest in 18 years amid a mystery UK-wide spike in mortality which experts say cannot be blamed on flu, cold weather or the ageing population.

Academics it could be a sign of health and social care services across the UK struggling to cope as a result of shrinking public investment and called for an urgent inquiry.

Read more: Record A&E delays blamed on influenza

In Scotland, the latest figures from the National Records of Scotland show that there were 7,552 deaths in January 2018.

This is the highest since 2000, when there were 7,564 deaths, and the second highest since 1990. It is also more than 2000 deaths higher than the average for the same month during the previous five years, from 2013-2017.

This coincided with a record number of patients waiting more than 12 hours in A&E, which the Scottish Government said at the time was partly due to hospitals struggling with a high number of flu cases.

However, Health Protection Scotland, which monitors flu every winter, recorded only 30 deaths from acute respiratory illness including flu this season.

Jim McMenamin, of HPS, said this was at the lower limit for recent years and that incidences of flu GPs reported were not "anything like" the high levels observed in 2010/11.

Read more: Flu surge blamed for blanket shortage at Glasgow hospital

It comes as a report in the BMJ found that 93,990 people died in England and Wales in the first seven weeks of 2018.

This compared to an average of 83,615 during the same period in the previous five years.

The authors - Lucinda Hiam at the London School of Hygiene & Tropical Medicine and Danny Dorling at the University of Oxford - noted that this had occurred despite mild weather, and that the proportion of deaths due to respiratory disease - including flu or pneumonia - was in line with that of previous years.

However, they said it had coincided with the cancellation of thousands of non-urgent operations across England and Wales, a move which they said was a "clear sign of a system struggling to cope".

They note that spending on health and social care year on year in the UK has increased at a much slower rate during the past five years than previously, and the growth in life expectancy across the UK has stagnated since 2010.

Read more: Increases in life expectancy 'have ground to a halt'

Professors Hiam and Dorling argue that there remains “a clear lack of consensus” over the reasons for the recent rise in deaths, but call for an urgent investigation by the Health Select Committee of the House of Commons.

Professor Dorling said he believed flu was being blamed to avoid looking at "the far more difficult reasons" behind the spike in deaths.

He added: "We need a select committee inquiry and Scotland could have its own inquiry."