A document that helped Apple gain an injunction against sales of the Samsung Galaxy Tab 10.1 in Europe, appears to misrepresent the device's similarity to the iPad.
A side-by-side comparison of the two tablets features a 'squashed' picture of the Galaxy Tab, making it look identical in size and shape.
Apple told the court that Samsung had "slavishly" copied its designs.
It is unclear where the original image came from, or if it was used in error.
When presented in the correct aspect ratio, the Samsung's screen appears longer and narrower than its American rival.
The story was first reported following an investigation by Webwereld, a Dutch IT news site.
The 44-page document, submitted by Apple's lawyers, Freshfields Bruckhaus Deringer, contains a number of other images which do not appear to have been altered.
Samsung is currently banned from importing, selling or promoting the Galaxy Tab 10.1 in the majority of European countries.
Apple is seeking to extend the injunction to the Netherlands, where many technology companies import their goods into the EU.
It is understood that the judge involved in the German case made his ruling based on a physical examination of the two tablets, rather than relying Apple's paper submission alone.
Patent law blogger Florian Mueller told BBC News that attempting to deliberately mislead the court would have been extremely foolish, given possible criminal penalties.
"I cannot imagine that any sane person would take a risk and intentionally manipulate evidence in this context.
"With different product versions being sold on different continents, and different pictures showing up at different points in time, someone may have been confused, but that's the worst-case scenario I can realistically imagine here," he said.