The Dutchman arrived at Spurs in 2014 but is still the subject of a legal dispute.
When he left Utrecht for Swansea in 2011, for a fee reported to be around £1.5 million by the BBC, the Dutch club believed they had agreed a sell-on clause as part of the deal.
However, as he left for Spurs as part of a part exchange deal Utrecht received no cash, which they felt was unfair.
Voetbal International are reporting the new developments regarding Vorm. The Dutch club will be going to CAS after appeals to FIFA have already fallen on deaf ears.
If they win the case Tottenham and Swansea will need to come to an agreement over a valuation for Vorm and Gylfi Sigurdsson – the Spurs player who went in the other direction along with what the Daily Mail said was £3.5 million.
This case looks set to rumble on for a while yet and both Swansea and Tottenham will need to get involved if Utrecht win the case.