Two Turner paintings stolen from the Tate galleries' collection eight years ago have been found.

The paintings, both 19th Century biblical works insured for �24m and now worth about �50m, were taken while on display in Frankfurt, Germany.

Described as two of Turner's most significant paintings, the works were found intact but without their original frames.

Shade and Darkness: The Evening of the Deluge and Light and Colour (Goethe's Theory): The Morning After the Deluge are now back in Britain and will go on display at Tate Britain on 8 January.

Tate bosses were reluctant to talk about the recovery as it could hamper the chances of finding a third artwork, from a German collection, which was stolen at the same time.

The works are now back in the UK

German artist Caspar David Friedrich's Nebelschwaden is still missing.

Shade and Darkness was actually recovered in July 2000, but the discovery was kept secret while investigations continued.

Light and Colour was recovered on Monday and both paintings were brought back to the UK on Wednesday.

Tate director Sir Nicholas Serota said: "These two paintings are among Turner's most important works and, in their references to Goethe's colour theories, show him to be at the forefront of European intellectual inquiry."

The two Turners were stolen from the Schim Kunsthalle in Frankfurt while on loan to the exhibition Goethe and the Visual Arts.

The three thieves and their driver were arrested in 1995 and convicted in Germany four years later.

Concerned

As a condition of the loan from Tate, the paintings were insured for �12m each in 1995.

Following the theft, Tate made a claim and the insurers settled for the full insured sum of �24m, a move which meant the title to the paintings passed to the insurers.

This was subject to an agreement that Tate should have first option to re-purchase them if they were recovered.

By 1998, Tate had become concerned that the paintings had not been recovered and, as a result, a large amount of money in the insurance fund was lying dormant rather than being used for any benefit.

A deal was struck whereby Tate bought back the insurers' title for �8m.

The former Tate director of programmes, Sandy Nairne, co-ordinated the recovery investigation.

He and the Tate's head of conservation, Roy Perry, have both seen the paintings and agree they are genuine and in good condition.

Although the paintings are now highly regarded, critics at the time were less charitable.

When it first appeared, Shade and Darkness was described by The Times as a "ridiculous daub".