The Denver District Attorney’s office said it is investigating allegations of theft at the organization, but won’t say how much money was allegedly stolen. A former volunteer with the group estimates the theft at $50,000 minimum.

A hospital spokeswoman Natalie Goldstein, told 7NEWS that the Children's Hospital Colorado Foundation did not issue a cease and desist order.

"We simply asked the organization to refrain from using our name until the independent investigation is completed," said Goldstein said.

A former volunteer with Fired Up for Kids, who asked to remain anonymous, told 7NEWS she left the group after questions were raised about finances.

She said online purchases were made on the company’s account that included a trip to Disneyland and tickets on Frontier Airlines.

Kirsten Hamling Was Only One With Access To Fired Up For Kids Account, Volunteer Says

The volunteer said owner Kirsten Hamling was the only person with authorization to access the account.

Through her attorney, Hamling denies any wrongdoing and did not return phone calls seeking comment.

When a 7NEWS crew went to the company’s address on the 16th Street Mall, a woman at the front desk of the shared business suite said Hamling was no longer there.

Firefighter: Burn Unit Patients 'Suffering'

Aurora firefighter Mitch Harr is Mr. June in the 2011 calendar. He told 7NEWS he feels betrayed and hurt that all calendar money may not have gone to burn victims.

"It's disappointing; overall disappointment," said Harr. "It's all about that burn unit right now. And that's what we want to preserve."

Sales of the 2012 calendar have been suspended. As 7NEWS first reported Wednesday night, former volunteers with the previous calendars have started to create a new nonprofit called "Colorado Firefighter Calendar." Once that organization is up and running, the calendars will be sold again, benefiting burn victims.

"Everyday that a calendar is not sold, it's the kids, it's those faces in that burn unit, that are suffering," said Harr.

Attorney: Company Is Not A Charity

Hamling’s attorney, Molly Jansen, issued a news release that states in part: Hamling is the sole owner of the for profit company, Fired Up For Kids, Inc. The attorney said the company is not a charity and is not designated as a not-for-profit organization through the Children’s Hospital or the federal government.

The release goes on to state: Ms. Hamling graciously donated money from Fired Up For Kids, Inc., to the Children’s Hospital, but in no way was contractually obligated to donate all proceeds to The Children’s Hospital.

It further states: Ms. Hamling abided by the terms of the agreement with The Children’s Hospital. At no time did she mismanage funds or withhold funds from the Children’s Hospital and vehemently denies all allegations to the contrary.

While Hamling’s attorney says the organization wasn’t obligated to donate all proceeds to the hospital, 7NEWS has reviewed news releases issued by her own public relations firm, Traction Communications, which state that all calendar proceeds benefit The Burn Center at The Children’s Hospital.

There are questions about what type of firm Fired Up For Kids is.

The attorney claims it is a for-profit business, but 7NEWS found records at the Secretary of State’s office, which shows it is registered as a not-for-profit business.

The company’s website has been changed.

In September it stated that “all proceeds from calendar sales” went to The Children’s Hospital Burn Center.

The website now states it donates a “portion of the proceeds from special events and the calendar” to the hospital.

The head of The Children’s Hospital Foundation referred phone calls from 7NEWS to a spokesperson for the hospital itself.

Goldstein re-issued a statement originally sent out Wednesday stating: The Children’s Hospital Colorado Foundation is working to review the Fire Up For Kids program. Our priority through this review is to safeguard the charitable contributions made by donors to this organization; uphold the selfless work by firefighters and volunteers; and uphold the public trust in this important philanthropic activity in support of the work of Children’s Colorado.

Several former volunteers at Fired Up For Kids have decided to start their own nonprofit to continue raising funds for Children's.

Attorney Bernard Gehris told 7NEWS that he filed papers with the Secretary of State's Office on Tuesday. He said the new nonprofit, called Colorado Firefighter Calendar, Inc., will seek tax exempt status from the Internal Revenue Service.

He said net proceeds from those calendar sales will go to the burn unit at The Children's Hospital and to promote fire safety and awareness.