In the news

From the failing fake news Gruaniad:
https://www.theguardian.com/world/2006/mar/01/law.emmabrockes

According to section 30, subsection (7) and (7A) of the Police and Criminal Evidence Act 1984, to "de-arrest" is to allow that "a person who has been arrested under any act of law at a place other than a police station, shall be released before reaching a police station if a constable is satisfied that there are no grounds for keeping him under arrest". Unlike being released with no further action, being de-arrested means that the record of the initial arrest is removed.

What isn't spelled out is that de-arresting someone does not preclude them from being rearrested moments later for something else.