Three sketches by Spanish master Goya that have been missing for 130 years will go on sale in London in July for an expected price of up to 3 million pounds.

The three, "Witches and Women", "The Constable Lampinos stitched inside a dead horse" and "Repentance", were last seen in public at a sale of Goya sketches in Paris in 1877.

Christie's, which will be auctioning the works on July 8 on behalf of the Swiss owners, said they were in good condition because they had had been kept away from daylight and had never been framed.

"Each one is from one of the artist's celebrated private albums, and they illustrate to perfection the inexhaustible fertility of Goya's imagination," said Benjamin Peronnet, head of Christie's Old Master and 19th century drawings division.

The three works, described as the most important group of Goya sketches offered for auction in more than 30 years, will be sold separately but are expected to collectively fetch between 2.1 and 2.9 million pounds.

No one in the art world knew where the sketches were until they were put up for sale. A handful of others are still missing.

The three are taken from two of Goya's private sketchbooks and are still on the mounts used for the 1877 sale. Two of the sketches failed to sell at that auction.

The Swiss family who have them had no idea they were missing and are unclear where they got them.