Michael Tracy McFadden, 46, was freed from a Colorado state prison on Tuesday

A convicted serial pedophile who was sentenced to more than 300 years in prison has been released on a technicality.

Michael Tracy McFadden, 46, was freed from a Colorado state prison on Tuesday, after an appeals court found that his 2015 trial had been delayed beyond statutory requirements and tossed the conviction.

McFadden cannot be retried on the charges of sexually molesting six young boys and girls, the Colorado Court of Appeals ruled. He will not have to register as a sex offender.

'We are without remedy,' Mesa County District Attorney Dan Rubinstein told the Daily Sentinel. 'I am appalled.'

Prosecutor David Waite, who tried the case, said that McFadden would befriend people with young children and 'groom them pretty heavily'.

McFadden would often take the children into the woods on the pretext of going dirt biking or four-wheeling, and molest them, Waite said.

McFadden had been held at Arkansas Valley Correctional Facility (pictured) until his release on Tuesday. He had originally been first eligible for parole on February 12, 2331.

His trial was delayed after defense lawyers sought to include provisions into the juror questionnaire to aid them in selecting jurors.

The defense twice agreed to waive speedy-trial trial requirements, according to Rubenstein.

However the appellate court found that McFadden 'did not expressly waive' his right to a speedy trial, and ruled that the trial had been delayed beyond Colorado's speedy-trial requirements.

McFadden had been held at Arkansas Valley Correctional Facility until his release on Tuesday.

He had originally been first eligible for parole on February 12, 2331.