The ceiling collapsed at the Milton Keynes Audi showroom sending 20 vehicles falling through to the workshop part of the showroom below.

The building was completed by BDB Design Build Ltd  last August at a cost of  £7m.

Showroom owner Jardine Motors Group said: “The building was specifically designed and constructed in 2014 to include a car park above the workshop area, accessible by a ramp at the rear of the building.

“There was nothing unusual about the number of vehicles parked on the roof at the time of the collapse and the load was significantly within design limits.

“Although not a unique feature for a modern car dealership, this is one of only two Jardine Motors showrooms with this facility.”

BDB is currently building another Audi showroom on Wearside.

The Enquirer contacted BDB to ask for a comment but has received no reply.