The prime suspect robbed the store on Friday night in Farsta, southern Stockholm, although the full details weren't revealed until late on Sunday as the police hunt continued.
The woman working in the store at the time of the robbery was handcuffed and threatened with a pistol by an unknown thief with long hair.
"His make-up was very well done, with blackened eyebrows and very long eyelashes," the jeweller told the Aftonbladet newspaper.
"I figured that he must have had help from a woman because the make up was so well done."
Police admitted they were unsure of whether the robber was "a man, woman, or possibly a transvestite", and confirmed that some jewellery was taken.
The armed robbery, which continued for six minutes, was facilitated by a suspected accomplice who was dressed up as Father Christmas, and stood outside the store performing what the worker called "cheap tricks" for other shoppers. Witnesses reported that the man's face was heavily covered in brown make-up.
Emilia Haglund, a 20-year-old who was in the shopping centre, was among those distracted by the man in the Santa costume.
"He distracted us so we'd look the other way to a different store. He followed after us for a bit and tried to talk, and was behaving really strangely," she told the paper.
Police have launched an investigation into the matter.