Painted ceiling panels at the Sheldonian Theatre are being put back in place at the end of a four-year repair project.

The 32 panels were taken down in 2004 to allow essential repairs to the ceiling cornice at the historic Broad Street building.

It was discovered that the panels - showing "truth descending upon the arts and sciences to expel ignorance from the university" - were in dire need of repair.

Now the project is nearing completion and it is hoped all the panels will be back in place by the end of October.

A time capsule is being hidden behind one of the panels, to continue a long-standing tradition.

Richard Pelter, director of Bristol-based International Fine Art Conservation Studios - which has led the project - said: "After 8,000 hours' work, the project is almost finished and there are only about 10 panels left to put back up.

"Then there will be some final adjustments and we will retouch some of the paintwork.

"A time capsule is going up behind one of the panels and we will include a computer disc with some digital photos and perhaps a pair of workmen's boots."

Mr Pelter estimated the four-year project would cost in excess of £1m.

As part of the work, any flaking paint was fixed, and discoloured varnish removed. The paintings were removed from their timber frames and old lining canvas and glue taken off the back.

Once the timber stretchers were fixed, the paintings - some of which are six metres long - were reattached, varnished again and stored, ready to be returned.

Jeffrey Hackney, chairman of curators at the Sheldonian, said: "I am very pleased with the work that has been done and I think people will be thrilled to bits with it."

When the panels came down in 2004, a pair of trousers was discovered, plus a note from their owner, Frank Morrill, of W Morrill & Son, picture liners, dated March 6, 1901.