The mother of a Romanian art heist suspect has admitted to torching seven stolen masterpieces, including works by Picasso and Monet, the Mediafax news agency reported Tuesday.

The mother of suspect Radu Doragu said she incinerated the artworks, valued at over 100 million euros ($130 million), in her stove in a bid to "destroy any evidence".

"After the arrest of my son in January 2013, I was very scared because I knew that what had happened was very serious," Mediafax reported Dogaru's mother as saying, citing court documents.

"I placed the suitcase containing the paintings in the stove. I put in some logs, slippers and rubber shoes and waited until they had completely burned."

The court documents appear to confirm earlier fears, after it was reported in May that investigators were combing through ashes found in her home.

Six Romanians will stand trial in August for what has been called the "theft of the century".

The seven masterpieces were swiped from Rotterdam's Kunsthal museum on October 16 in less than 90 seconds.

The heist gripped The Netherlands and the art world as police struggled to solve the crime, putting 25 officers on the case.

The works stolen include Picasso's "Tete d'Arlequin", Monet's "Waterloo Bridge" and Lucian Freud's "Woman with Eyes Closed".