Santia Consulting Ltd issued a statement on Friday saying the source of the asbestos contamination in the school "still remains in place consisting of substantially damaged asbestos insulating boards (AIBs) in the ceiling voids, damaged AIB in the room heaters and repeated damage of AIB window panels within classrooms".

BBC: Asbestos: More concerns over Cwmcarn High School future

The 311 individual panels from the window reveal a Christian history of the world, as told in the Bible, from Creation to the Last Judgement.

BBC: Metal York Minster 'orb' displays medieval stained glass

Inside, visitors can see five newly-conserved glass panels from the window.

BBC: Metal York Minster 'orb' displays medieval stained glass