The head of the NSW Law Society says prosecutors have never made use of recent laws removing a suspect's "right to silence" and they should be ditched.

The changes, brought in two years ago, allow judges and juries to take a negative view of an accused person who fails to mention something during police questioning that they could reasonably be expected to mention, and that they later rely on in court.

The changes do not cover some suspects, including children.

They were brought in by then-NSW Premier Barry O'Farrell following a spate of drive-by shootings in Sydney's west and passed through parliament in March 2013.

But the laws have never been used and they should be taken off the statute books because they violate fundamental rights, Law Society president John Eades said on Sunday.

"It is an essential tenet of the criminal justice system that the prosecution has to prove its case beyond reasonable doubt," he said.

"It is not the responsibility of the accused to prove his or her innocence.

"The amendment is clearly unfair and unworkable and the NSW government should now consider its removal."