How to disable CSV Export button

I have an event running, but I want to hide the export button on the detail event screen. I cannot find an option for this.
In the options menu (Joomla 2.5) I can disable the rights for front end user management, but I do not see any effect.
Urgently looking for a solution.......

Hi Rene

Could you please give me more information ? The button is showing for what users group at the moment ? Please let me know so that I can check it more details for you ? The simplest way is submit a support ticket sending me administrator account of your site so that I can help you to check it!

Regards,

Tuan