The agency ruled that 19-year-old Sofia Englundh from Vällingby near Stockholm can not change her name to Sofia "Dark Knight" as it is the name of the recently released Batman film starring the posthumous Oscar winner Heath Ledger.
"I love the film and the actors, Christian Bale and Heath Ledger," Sofia Englundh explained to The Local.
"Also I don't have a middle name and thought it might be nice."
According to the agency's guidelines a name can be rejected as inappropriate if it is considered offensive, describes genitalia or is a swear word.
"I can understand if it is offensive, but this is just the name of a film. What's the problem?" Englundh said.
The guidelines also state that first names can be rejected if they resemble surnames and in this case the agency has ruled that as there are a number of people with the surname "Knight" already resident in Sweden it is not appropriate.