Former hostage Joshua Boyle's trial could be on hiatus for months while the lawyer representing his estranged wife appeals a provincial court's decision to allow evidence about the couple's sexual history.

Today, Justice Peter Doody reconvenes the high-profile trial that has exposed details the couple's years of captivity in Afghanistan after being taken hostage by Taliban-linked terrorists in 2012, and Caitlan Coleman's allegations of physical and sexual assault by her husband.

Boyle is being tried on 19 charges — including two counts of sexual assault with a weapon, three counts of unlawful confinement and one count each of administering a noxious substance, assault with a weapon and public mischief. The offences are alleged to have occurred between October and December 2017, when Boyle and Coleman returned after five years as prisoners in Afghanistan with their three children, all born in captivity.

Boyle, 35, has pleaded not guilty.

Before today's court hearing, the trial judge ruled the defence could question Coleman about her mental health medical records and the couple's previous sexual history. That ruling came after two weeks of lengthy legal arguments that were closed to the public.

Ian Carter, Coleman's lawyer, said he'll challenge the court's ruling and will file an appeal in Ontario's Superior Court.

Carter told CBC News Tuesday this will delay the trial because the court will not be able to hear further evidence — including evidence from Coleman, who is still under cross-examination.

Canada's Criminal Code contains several 'rape shield' laws that prevent the defence from using emails, medical records or an alleged victim's past sexual history to prove a pattern of sexual behaviour.

The court can make an exception if the accused or his lawyers demonstrate that including those details is of value.

Justice Doody ruled, in a written decision on a section 278.9 application, that the defence can introduce evidence that was in the possession of the accused — a medical record from a January 2018 session Coleman had with a psychologist.

Caitlan Coleman leaves court in Ottawa on Wednesday, March 27, 2019. (Sean Kilpatrick/Canadian Press)

The psychologist's notes indicate Coleman said her husband began assaulting her in December, 2017. Coleman told police and the court that the physical and sexual assault began in October, 2017.

The judge also will allow evidence about Coleman's sexual history after a section 276.2 application. According to the judge's written decision, the defence can ask Coleman about the couple's prior sexual activity, including consensual anal and vaginal intercourse, sexual acts involving ropes and consensual biting acts.

Coleman previously testified that Boyle forced her to perform these acts against her will.

The CBC's David Thurton can be reached on Facebook, Twitter or at david.thurton@cbc.ca