Spike in cases for mid April

[DoctorTone]

Hi,
Firstly, thanks for all your hard work on this, it's a valueable resource.

Whilst visualising the data I noticed a large spike for cases around April 11th - there seem to be in excess of 8,000 new cases on that day. This doesn't appear to be reflected in any of the other datasets that I have seen, such as Wikipedia or BBC for example. Comparing the data to Wikipedia's (which they also say they have taken from the government's website) there seems to be small anomolies round this time and then a large jump for April 11th. Is this an error or is there another explanation - the new cases for each country don't seem to add up to anything like this number either?
Many thanks,
Tony.