A report in New Scientist describes a study of genetic sequencing of coronavirus cases in the UK.
It concludes that coronavirus was introduced to the UK by travellers from mostly Spain, France and Italy.
The coronavirus was introduced and spread throughout the UK by 1356 people who travelled here mostly from European countries, according to a studyby researchers in the Covid-19 Genomics UK Consortium.
The study has not yet been peer-reviewed. The researchers analysed genetic sequences from 20,000 coronavirus cases in the UK and used this to build a family tree. This revealed the lineage of the different infections and allowed the team to trace their origins.
They estimate that 34 per cent of these original coronavirus cases were people who arrived in the UK from Spain, 29 per cent from France and 14 per cent from Italy. The researchers estimate that most introductions of the virus to the UK happened in March.
You can read more in the New Scientist here. The preliminary report is here in virological.org