The Flood tribunal may have asked to see Mr Liam Lawlor's three mobile phones to check the information stored on them.
The latest models of one of the brands given to the tribunal, Panasonic, allows storage of up to 400 numbers.
The phone may also have a built-in recorder and so contain a message recorded by Mr Lawlor. The last 10 calls dialled and received would also be contained on such a phone. It may have stored up to 30 text messages received or made.
Another phone in the tribunal's possession, the Motorola Timeport, may have been chosen by Mr Lawlor as it allows travel all over the world and would have been useful for business ventures in eastern Europe and visiting his children in the US. This phone allows about 150 names and numbers to be stored and 20 text messages.
The Philips Savvy, the third phone, is a basic model which allows storage of numbers and text messages.
It is unlikely the Flood tribunal would need the phones to get information on calls Mr Lawlor made. If his phones are paid on a billing basis either Esat Digifone or Eircell would have information on calls made and received.
If a phone is switched off Eircell phones can be turned on without the customer's pin code, a spokeswoman said. Phone calls can also be monitored.
The Eircell spokeswoman added that such action would only be taken following requests from the Assistant Garda Commissioner's Office and in accordance with statutory requirements.