The Evidence Amendment Bill, which aims to improve the court experience of vulnerable witnesses, has passed its second reading in Parliament with unanimous support.

Justice Minister Amy Adams says the Bill introduces new safeguards for children and victims of sexual violence who give evidence.

"Being questioned in court can be a distressing experience in the best of circumstances. This Bill will help to lessen the trauma of giving evidence for the most vulnerable witnesses," Ms Adams says.

The Bill creates a presumption that children under 18 will not give evidence from the witness box.

Instead, the court will hear their evidence through the video of their police interview, via closed-circuit television or from behind a screen. All child witnesses will also be automatically entitled to have a support person with them when giving evidence.

The Bill also introduces new protections for video records of Police interviews with child complainants, and with witnesses of any age in sexual and violent cases. Restrictions and safeguards on access to such records will reduce the risk that sensitive video evidence is misplaced or used inappropriately, Ms Adams says.

In addition, the defence will need to apply to the court before a trial begins for permission to introduce evidence of a complainant's sexual history with a person other than the defendant. The defence can seek the judge's permission to introduce this evidence at any time during the trial.

"While we can't completely eliminate the stress victims of sexual violence face when they give evidence, these changes will help ensure that victims who are brave enough to hold their attackers to account are not re-traumatised by the court process," Ms Adams says.

Other provisions in the Bill respond to recommendations in the Law Commission's 2013 review of the Act, and ensure evidence laws are up-to-date and working as intended.

The New Zealand Law Society's Law Reform section made submissions on the Evidence Amendment Bill in August last year.