A Surrey B.C. couple accused of shaking their baby girl are taking their case to court to try to prove she has a medical disorder, in an attempt regain custody of their three children.

The couple's three children were taken away by the B.C. Ministry of Children and Families 2½ years ago after the allegation of abuse first arose.

'From the start, we have been in an uphill battle to prove our innocence,'—Mother of three

The two boys, aged four and three, and the girl, who was just a baby at the time, have since been placed in foster care.

Outside a courthouse on Wednesday the couple, who have never been charged in the case, said their girl was never abused.

"We've asked for a second medical review and the ministry stated that they weren't interested in seeking that," said the mother, who can't be named because of a court-ordered publication ban that restricts any information that might identify the children involved.

"From the start, we have been in an uphill battle to prove our innocence, because we did not shake our baby. We did not harm any of our children," she said.

They claim the girl suffers from a rare medical condition and they have expert opinions to back them up, which they intend to present in court.

"We do know that we have 10 medical experts that have submitted reports that state that it's not shaken baby," said the mother.

Ministry documents back claims

The couple said they obtained internal documents last spring from the ministry which they say indicate their daughter likely suffers glutaric aciduria, a rare disease often mistaken for child abuse, because it can result in swelling of the brain and bleeding.

They said one of their sons tripped over the girl, which combined with the rare disease, led to a misdiagnosis of abuse.

But on Wednesday the court heard from two witnesses who originally informed the court about their suspicions that the couple's children were being abused.

Pastor Michael Hoffman and his wife Elizabeth were in charge of a church in Hope and were friends with the couple at the time.

Michael Hoffman advised police that based on psychology classes that he took at seminary that he believed the mother was suffering from post-partum depression and that she had Munchausen's syndrome by proxy, an uncommon condition in which a person harms another in order to gain attention.

The pastor's wife testified that the two boys seemed small for their age and that the little girl started looking increasingly listless.

But it also came out in court that both couples had started running rival businesses offering music lessons and their friendship deteriorated around the time the baby girl was born.

The parents who work as night janitors have hired high-profile defence lawyer Doug Christie to represent them in court.

Outside court on Wednesday, Christie said many parents often lack the resources to fight allegations of abuse.

"[It is] very difficult emotionally for parents who are innocent — and there are some — and that's what this case is about. All the power it seems to me is on the side of state in these cases," said Christie.

"Many experts and many doctors make their entire living working for government authorities and the case of Dr. Charles Smith in Ontario has demonstrated how dangerous that can be," he said, referring to the case of a doctor who was found to have falsely testified in a large number of court cases.

"People were put in jail for accusations of shaken baby syndrome and those people have served time for crimes they did not commit. That's why this becomes a very serious matter when you make allegations of this kind and base it entirely on opinion evidence," said Christie.

Support found online

The couple said they have received a lot of support from an online campaign they have been running, using Facebook, Twitter and blogs, and from a recent fundraiser.

"We're just glad that after two-plus years we're finally able to come before the court and present our medical evidence that we do have … and we are praying that at the end of the day the truth will come out and our children will be restored to our home," said the mother.

Since their children were taken away, the couple said they have only had limited visitation rights.

"Six hours a week is absolutely nothing … the visitations are actually quite hostile. We have been in every visitation supervised," said the mother.

"They have actually lost weight. They are actually about five pounds lighter than when this thing first started all this," said the father, referring to the boys.

" We are devastated by all the time we miss with her," said the mother, referring to her daughter.

The court hearing is expected to take three weeks.