Megan Huntsman
Megan Huntsman has been charged with six counts of murder   Reuters

The husband of the woman charged with murdering six of her newborn babies has reportedly denied being their father amid growing speculation they could have been born as a result of an extra-marital affair.

Darren West found the murdered babies hidden away in cardboard boxes in a garage at his home in Pleasant Grove.

Police said West had no knowledge of the babies who were either strangled or smothered at birth.

His estranged wife, Megan Huntsman, 39, admitted to killing six of the babies – a seventh was also discovered – it remains unclear why she has not been charged for this murder. She is currently being held on $6m bail.

Neighbour Aaron Hawker said: "He (Darren) has told me he has no idea where the babies came from. He has insisted that they were not his."

But speculation is now mounting whether the babies were as a result of an extra-marital affair while West was in prison on drugs charges.

Huntsman was kicked out of her home when her in-laws found out she was having an affair in 2011.

Hawker told MailOnline her in-laws agreed to let her live in the three bedroom home after their son was jailed in 2006 on drugs charges on the one condition she remained faithful to her husband while he was in prison and not see any other men.

But she was told to leave as soon as they realised she was being unfaithful.

"What I was told by Darren was that she began an affair and when her in-laws found out they told her to leave," Hawker said. "I do not know how long the affair went on for, but was told that it was with a co-worker.

"Megan left in 2011 and since then we have hardly ever seen her at the house. She would not come back very often and was told she was not welcome in the house."

Hawker admitted that he never saw Megan pregnant or even put on any weight.

"It is a complete mystery to me and my wife Kathie. Megan was always very shy, but she was very nice."

The bodies have been sent to a Utah medical examiner to determine the cause of the deaths.

DNA samples were also taken from Huntsman and her husband to confirm their identity as parents.