Lisa Biron
Lisa Biron will be sentenced in April after a jury found her guilty in Manchester, New England. (Facebook)

An anti-gay Christian lawyer has been jailed over eight child porn charges after filming a 14-year-old girl having sex with two men.

Lisa Biron, 43, from Manchester, New England, took the girl to Canada to make the film and encouraged her to drink, smoke cannabis and have sex.

In the past, Biron had done work for anti-gay Christian defence group Alliance Defence Fund.

She was charged with child sexual exploitation, transporting a child across state lines to produce child pornography and possession of child pornography.

During the trial, while Biron was being held in custody, she was also recorded telling her father that it was the girl's fault, saying: "She had a part in this."

An FBI agent who specialises in computer forensics retrieved pornographic images from a computer that was owned by Biron. He also found a sexually explicit video of the girl on a confiscated iPhone.

Graphic evidence 

Biron stood trial with the two men who had sex with the 14-year-old. The jury deliberated for less than an hour before finding all three guilty.

US attorney John Kacavas said the evidence against Biron was difficult to watch. He told WMUR9: "It was difficult to present because you were presenting very graphic evidence to people who aren't exposed to this on a daily basis, but in terms of putting the case together, it was relatively easy because the evidence was created by the defendant herself, and it was video evidence that really does speak for itself."

Helen Fitzgibbon, assistant attorney, said this was a straightforward case where a woman had used a girl as a sexual object.

The defence for Biron called no witnesses. Defence attorney James Moir said she is devastated: "This was a tough case from the beginning, as I think everyone on all sides knew. And I'm disappointed, of course."

Biron is due to be sentenced in April. Kacavas said the minimum sentence will be 25 years. The transportation charge carries a minimum sentence of 10 years and each exploitation charge carries at least 15 years.

She was arrested in September after one of the men who appeared in the film, Brandon Ore, 18, went to the police to report his and Biron's crimes.