• "De-arrested" - what about my DNA?

From BBC Wiltshire (dear knows why I subscribe to a news feed predominantly about Swindon of all places!):

A man at the centre of a police investigation into an explosion in Swindon has been de-arrested.

The 44-year-old remains in hospital with burns injuries after the roof blew off a block of flats on 23 December in the Toothill area of the town.

Wiltshire Police said no formal interviews had taken place and because he had not visited a police station all records of his arrest would be removed.

Now I wonder if his DNA was taken and whether it will now be destroyed.  Is "de-arrested" a real legal concept anyway?