MESA COUNTY, Colo. (KKCO) -- The father of Paige Birgfeld, whose murder remains unsolved, is renewing his request to the Mesa County Sheriff's Office to give up the case and turn it over to the Colorado Bureau of Investigation.

"I've asked for it to be moved to an objective agency of which the fog of corruption and cronyism and amateur police work doesn't reside," says Frank Birgfeld, Paige's father, "and the basic question is why not?"

On January 25th, Birgfeld sent a letter to the Mesa County Sheriff's Office. In the letter addressed to one of the sergeants, Birgfeld claims the sheriff's office lacks the skill to solve the case. He asks them to give up their "collective egos and move it on to someone who is capable."

He criticizes the sergeant for failing to meet with him in October and keeping the Birgfelds in the dark since that time. “It represents yet another instance demonstrating why your bunch is not up to the task of this investigation,” Birgfeld says in his letter.

In response to the letter, the Mesa County Sheriff's Office says they cannot comment on open investigations at this time.

Paige Birgfeld disappeared in June 2007. Her remains were found by a hiker just across the Mesa County line in Delta County on March 6, 2012.

When Paige's body was discovered, the sheriff's office told KKCO 11 News that tests on the remains didn't provide any obvious clues about what happened to the missing mother of three.