Frozen 2 is in development but details about the sequel to the hit Disney animation movie are frustratingly thin on the ground.

With Disney mum on the plot and other key aspects of the sequel, fans are coming up with plenty of theories of their own to bide the time until the release of the movie, expected in December 2019.

One such theory is that Elsa and Olaf could become romantically involved in the sequel and that the power of her love could be enough to turn him into a human.  Sounds a little bonkers to us, but then again Disney isn't exactly true to reality - talking candlesticks anyone?

Some of the other questionable theories around the plot include Elsa and Anna actually having a long lost brother in the form of Tarzan.  The thinking behind this connects to their parents having a baby boy after being stranded on an island thanks to a storm that destroyed their boat. 

Another theory speculates that Tinkerbell might join the line up of characters in the sequel. 

Development of the sequel has been painfully slow, with Kristen Bell freely admitting that Disney is in no hurry to get the sequel into the theaters. 

Quite the opposite, according to the star, as she says it's more important to Disney that they get the movie right than that they get the movie out.  

Asked whether work had started on Frozen 2, she told IGN: "We have not. We work consistently to do the openings of [theme] parks or the change of seasons at parks or the ice show or whatever. But they are not rushing the script. They have the luxury to not rush because everyone is going to be excited whether it comes out tomorrow or in five years. They're making it as perfect as they need it to be and we're on call to start recording whenever."