Doubtful Origin

Part of Fondation Constant's mission is to protect the legacy of Constant Nieuwenhuys. The foundation is usually informed when works on the market are thought to be a copy, false or misattributed to Constant. Each situation has different implications.

  • First situation: Infringement on copyrights - an existing work of art is copied by someone, who, without prior permission of the copyright holder/Pictoright, reproduces the work and/or makes the work available to the public-with the artist’s name or his own name. This is considered a breach of or infringement on copyright and will therefore be handled by the organisation that handles the artist’s Intellectual Property rights.
  • Second situation: Misattribution - a work is mistakenly attributed to the artist. Even though there might not have been the intention to deceive, these works must be unveiled to avoid the illusion for owners or potential buyers that the work represents a certain value as if it were an authentic work from the artist.
  • Third situation: Forgery - a work of art is created with a deliberate intent to deceive. These works are usually presented falsely as a product of another time and/or artist. This could concern copies of existing works of the artist (falsification) or newly created works in the style of the artist as a consequence of which the work can be misattributed to the artist. Both situations are considered a forgery and a criminal act and will therefore be handled by the justice department and Pictoright.

The negative effects of these dealings have an impact both on individuals involved, the value of the works of the artist, and on the art market in general. Fondation Constant is supportive in the fight against these activities. We have close ties to both Pictoright, the Dutch Criminal Investigation Department for Art Related Crime and parties such as the Art Loss Register, who are all dedicated to eradicating  criminal activities from the art market.

On this page we will post information on the doubtful art works we encounter and where we have encountered them. To avoid law suits we will refrain from mentioning the specific parties involved.

NB: Fondation Constant does NOT give out certificates of authentication. When a work adheres to our guidelines for authenticity we will add it to out digital catalogue raisonné.

Tips when buying art

  • Ask for documentation on the work of art. Original works usually are obtainted through offical channels and come with invoices, catalogue/exhibition listings and are mentioned in art books.
  • Ask for a provenance. Original works are usually easily traced back to their source, this list of previous owners is called a provenance. Original works of art come with a provenance.
  • Do a background check on the seller. Is the seller a well respected art gallery that is well known for selling the art of this artist?
  • Do a google search on the prices. If the selling price seems too good to be true compared to works you find at the well renowned galleries, it probably is. However, above a certain price level most galleries do not make their prices public.
  • If a work is sold as assigned to... instead of by... it usually means there is reasonable doubt about the work's origin.
  • If buying online, check the Terms and Conditions of the online resellerThey might already indicate that they are not responsible of the authenticity of the works they offer!

These are some rules of thumb that should give you an indication of a works authenticity. If after this checklist, you still are unable to reach a conclusion, you can contact Fondation Constant for an assessment. Go to Assessment, for more information.

Fondation Constant is a not for profit organisation and your donations are always welcome and ever necessary:

Fondation Constant cannot be held responsible and/or liable for any damages, costs, expenses, loss or grievances incurred by publication or the use of the content published with regard to "Copyright Infringement, Misattribution and Forgery" on this website.
Fondation Constant will only publish information on such works if, after expert research with regard to the work, the case etc, Fondation Constant is of the opinion that such work is not authorised or authentic. However, these publications are to be considered the opinion of Fondation Constant only. Fondation Constant does not accept any liability for damages, costs, losses etc. arising from such publication.

Read more
Title Year Technique Category CID
1980 ca Portret van Karel Levison Constant

Portret van Constant

1980 Watercolour Misattribution 7636
Schets naar Lijn zonder einde (vals), ca. 1962

Schets naar "Lijn zonder einde"

1962 Drawing Forgery 7614
1962 ca ZT-Sateliet

No title/Satellite

1962 Drawing Forgery 7611
2023 Aquarel, 1997

Copy of Femme et enfant

1997 Watercolour Copyright Infringement 7438
2023 Oil on linen, 1949

No title/Three Figure with Bird

1949 Oil painting Forgery 7430
2005 Watercolor, no yr, sign

No Title/Vegetation

1980 Watercolour Forgery 7429
2005 Gouache on paper, 1969

Rendition of Figuren in ruimte

1969 Watercolour Forgery 7428
2007 Graphic work, no year

No Title/Figures

1949 Graphic Work Copyright Infringement 7427
2008 Oil paint on paper, no year legible

No Title/Cameleon

1980 Watercolour Forgery 7426
2008 Paint on paper, 1950

No Title/Two Lizzards

1950 Watercolour Forgery 7425
2008 Watercolor on paper, 1987

Yet Another Copy of La belle noiseuse

1987 Watercolour Forgery 7424
2008 Watercolor on paper, no year

Copy of Junkies

1980 Watercolour Copyright Infringement 7423
2009 Gouache on paper, 1969

Another Rendition of Figuren in ruimte

1969 Watercolour Forgery 7422
2009 Mixed technique on paper, 1951

No Title/Abstract Work

1951 Drawing Forgery 7421
2011 Oil on canvas, date illegible

No Title/Unclear Brown Mess

1980 Oil painting Forgery 7420
2011 Oil on linen, signed

No Title/Grey-ish Mess With Childlike Figures

1980 Oil painting Forgery 7419
2011 Construction with plexiglass, 1956

Copy of Construction with Transparant Planes

1956 Construction Copyright Infringement 7418
2011 Watercolor on paper, no year

No Title/Black Dog or Cat

1980 Watercolour Forgery 7417
2012 Oil on canvas, no year

No Title/Landscape

1980 Oil painting Misattribution 7416
2012 Oil on canvas, no year

No Title/Baby

1980 Oil painting Misattribution 7415
2012 Watercolor on paper, 1987

Copy of Le Criminel

1987 Watercolour Copyright Infringement 7414
2012 Watercolor on paper, 1975

No Title/Horses..?

1975 Watercolour Forgery 7413
2012 Sketchbook, signed, no year I


1980 Drawing Forgery 7412
2012 Gouache on paper, 1949

No Title/Not Even Close to Cobra Figurines

1949 Watercolour Forgery 7411