Who Owns My Client Notes?

I currently work for a studio who provides my work permit. i am leaving at the end of the month to go to another studio (5 minute walk away and a direct competitor) and they are taking over my permit.

for the last 3 years, off my own back in note books i have bought, i have written notes for pretty much every session i have done with each client (clients have been provided for me by the studio). i think an important point is that no other trainer in the studio does this and it was not requested of me, nor is it in my contract.

many of my clients are planning to follow me to the new studio, a fact that my current employees are probably aware of and are obviously concerned about their business.

they are requesting and believe that my books belong to the studio i work in and should be left with them when i leave (whether the client moves or not). i believe they are my property and as such i should keep them, destroy them, pass them to my client if i chose to.

please can you help me from a legal point.. my current employer has actually stated they could take me to court over this and said there is something in the paperwork the client signs about it - which i have read and there isn't. ( i don't think they will and i would hand 'notes' over to avoid this) it is more a matter of principle and knowing for the future what to do to avoid it again.

thanks