The cost of keeping metadata for telcos and their customers will be as much as $400 million but Prime Minister Tony Abbott says the price of not storing electronic communication records is "incalculable" because it would lead to an "explosion in unsolved crime."

Mr Abbott on Wednesday broadened the case for storing metadata as proposed in the third phase of new counter-terror laws by linking it to policing of paedophilia and white collar crimes.

He visited the headquarters of child safety group Bravehearts on the Gold Coast in Queensland with Liberal MP Dan Tehan, who is the chair of the Parliament's independent and bipartisan intelligence committee, which is scrutinising the legislation.

Mr Abbott said the new laws that would force telcos to keep communications records for two years will help authorities deal with a "whole range of criminal conduct".