The paintings were discovered in a house in Madrid

Two paintings by Spanish artist Francisco de Goya have been bought by the Spanish Government for 1.75m euros (�1.2m) each on Thursday.

Before they were known to be Goya's work, the paintings were estimated to be worth only 1,500 euros (�1,075).

The two small religious paintings, Sagrada Familia (Holy Family) and Tobias y el Angel (Tobias and the Angel), were discovered by chance last year by an art expert for Spanish auction house Alcala Subastas.

Richard De Willermin, who specialises in 17th- and 18th-Century Italian and Spanish art, was appraising some other works in a home in Madrid when he spotted one of the paintings in a hallway.

"The owners had absolutely no idea what they had on their hands but Richard knew right away," said Alcala Subastas official Raquel Lombas.

The owners told De Willermin they had a similar painting in the bedroom, which turned out to be the second Goya work.

Experts at Madrid's Prado museum examined the paintings in March but declined to comment publicly on whether they were authentic Goyas before the auction.

The paintings are oil on canvas

"If there was any remaining doubt, now it is gone," said Lomas. "The Prado must have known something."

The Spanish government matched the bid of an anonymous prospective buyer. Under Spanish law, the government has the right to acquire historic works of art.

The government has two years to pay for the paintings.

Last month there was controversy over whether two paintings in the Prado museum, The Colussus and The Milkmaid of Bordeaux, were by Goya.

British Art Historian Juliet Bareau-Wilson claimed the works were not by the Spanish master.

She was backed up by Prado curator and Goya specialist Manuela Mena, who thought the works were painted by de Goya's daughter, Rosario Weiss.

But director of the museum, Fernando Checa, was adamant that the works were authentic.

"For the Prado, the two works are by Goya and they have been given out on loan as such," he told the leading Spanish daily newspaper El Pais.

Francisco de Goya is considered one of the world's greatest artists and one of the first "modern" artists.

His masterpieces include The Naked Maja, which hangs in the Prado.