The Prison Service is investigating how Massey managed to elude staff.
A Prison Service spokesman said:
This continues to be the subject of a thorough ongoing investigation and Mr Massey will be returned to prison custody as soon as possible.
We always press for the heaviest penalties for those who escape or attempt to escape.
More top news
A wet end to the month with a deluge of rain across much of southern Britain.
The most shocking finding is that 75 of 95 buildings found to have failed cladding fire safety standards were Category 3 failures.
Judges in the European Court of Human Rights have rejected a plea from the parents of terminally-ill baby Charlie Gard to intervene.