Recording phone calls

Is there any connector cable or device for an ipad to connect to a land based phone to record phone calls? I am in need of recording phone calls that take place over a land line phone in a business setting. Currently we use digingal recorders and we have a recording jack that is connected to the phone line and from the connecting line a mini jack extends off and can be plugged into the digital recorder to capture both callers voices.

Is there any such device to use with an ipad to replace my recoder? Currently we have been able to use speaker phone on the land line and the mic on the ipad to capture calls. This works ok for some of the time, but is hard when we have hard of hearing clients.