Can your GP and/or Specialist Phone ACC to ask about your claim
Only if you give your permission, preferable in writing.
You should verbally instruct your GP or any other medical/other health service provider not to speak with ACC and or to any of their service agents and provide them the form (or similar) that needs to be attached on the front of your files.
See form in following post
An Alert pops up when he/she or anyone else accesses your medical files reminding them that permission is required etc.
Get a copy of all your files from ACC.
Get a copy of your Personal Medical History file/s from your GP.
There is no sure way of preventing or even knowing ACC will not speak with anyone about you.
Write to them stating that they are under no circumstances to contact anyone regarding your claim or claims by telephone, everything must be in writing and copy sent to you each and every time.
You have a right to allow or disallow any parts of your Medical History being provided to your GP.
If it's not injury related then ACC should not be requesting it.