MADRID- New official data in Spain showed on Wednesday that many more people have died than usual this year than the recorded number of coronavirus fatalities and revealed a shocking 155% spike in mortality at the epidemic's peak in early April.

Experts believe the additional deaths include cases where the cause is hard to establish due to underlying conditions, and fatalities among people who avoided hospital treatment for other problems due to the fear of contracting COVID-19. 

Spain has had one of the world's worst coronavirus outbreaks, recording an official death toll of 27,127 and seeing its tourism-dependent economy pulverised during a severe lockdown that helped curb the disease.

The National Statistics Institute (INE) said it was starting an experimental series monitoring the weekly mortality rate to help shed light on the impact of the pandemic.

A total of 225,930 people died in Spain in the first 21 weeks of 2020 - 43,945 more than the same period of 2019 and 16,818 more than the health ministry's current total confirmed coronavirus death toll.

The INE data was consistent with figures from the National Epidemiology Centre, which estimates mortality comparing deaths recorded across civil registries with historical averages.

Overall mortality in Spain jumped its highest, 155%, in the worst week of the coronavirus outbreak in early April from the same period a year earlier, according to the INE data.

Supporting the Spanish government's belief the worst is over, on the last week analysed by the INE, between May 18-24, mortality was at the same level as a year earlier.

Elderly people over 90 were the hardest hit so far this year, with 27% more deaths over the 21-week period, while 25% more died among those aged 85-89. There was hardly any difference from a year earlier in groups under 54 years old.

(Reporting by Emma Pinedo; Editing by Andrei Khalip and Andrew Cawthorne) ((emma.pinedo@thomsonreuters.com; 91 585 85 33; Reuters Messaging: emma.pinedo.thomsonreuters.com@reuters.net; Twitter: @ReutersEspana))