Production of a gold ring for the film began after Mr Hansen's death from cancer in August, although he had been working on designs for several months.
His son and studio manager, Thorkild Hansen, said the film's management team selected the ring from 12 designed by his father.
"I was quite surprised at the time spent choosing it. It's a very important part of the film."
Up to 40 of the rings would be needed during filming, said Mr Hansen, who would not reveal how much the contract was worth.
"There's only one ring in the movie but there are many actors who wear it. For some actors we've had to make up to six different rings. The props department has to be covered in case one gets lost or damaged."
The design was plain gold with no stone, similar to a wedding ring but heavier.