HARTFORD, Conn. (AP) - Authorities in Connecticut and Tennessee are investigating a charity that raised money it said would go to those affected by last year's school shooting in Newtown, Connecticut's attorney general confirmed Tuesday.

U.S. Sen. Chris Murphy, a Connecticut Democrat, sent a letter Tuesday to IRS Commissioner John Koskinen calling for an investigation of the 26.4.26 Foundation.

Only $30,000 of the $103,000 taken in by the 26.4.26 Foundation was used for the organization's purpose, co-founder Ryan Graney of Nashville told The Associated Press last week.

Investigators in Tennessee are looking into the organization and another co-founder, Nashville-based endurance athlete Robbie Bruce, according to Connecticut Attorney General George Jepsen. He thanked his counterpart in Tennessee, Robert Cooper Jr., in a letter written Monday that was obtained by the AP.

"Cooper fully understands the gravity of the situation," Jepsen said in an interview Tuesday.

Graney said she inquired about the rest of money but Bruce cut off contact with her, so she filed complaints with the FBI and Cooper's office. Cooper's office and the FBI have said they do not comment on specific investigations.

But special Agent Daniel Curtin, an FBI spokesman, said in an email that there are ongoing fraud investigations related to Newtown.

"The FBI investigates these types of frauds thoroughly and with a real sense of urgency because we recognize that legitimate charitable organizations are harmed by fraud and, in the case of Newtown, victims' families are, in a sense, re-victimized," he said.

Bruce didn't return repeated telephone messages. No one answered the door at his apartment last week.

The idea behind the 26.4.26 Foundation was for runners to participate in marathons, raising money for each of the 26 miles they ran and dedicating each mile to one of the 26 victims of the 2012 school shooting in Newtown - 20 children and six educators. The fundraising effort was featured in Runner's World magazine and was the subject of several local news stories.

"I will appreciate receiving information you may learn about Mr. Bruce's current location or address so that my office can continue our diligence in accounting for all Sandy Hook-related fundraising and ensuring that it is used as intended for the Sandy Hook community and victims," Jepsen wrote to Cooper.

The charity held its first marathon in Nashville a week after the shooting, with more than 1,000 participants raising $30,000. Another was held in New Hampshire last April. More than 1,400 runners raised about $22,000 for the foundation, organizers said. The charity also received donations from runners in other events, Graney said.

The $30,000 was presented last January by Bruce to a youth sports center in Newtown.

Graney said she noticed something was amiss last spring, when she discovered suspicious charges to the foundation's PayPal account.

"I saw there was $1,200 billed for paddle boards," she said. "I went on (Bruce's) Instagram page, and h e had posted a picture of a paddle board in the back of his truck."

Graney said she confronted Bruce and he promised to meet her and go over the organization's finances. She said he never showed up and then cut off contact with her in September.

"If I knew what was going on, I would have stopped it sooner," she said. "I feel terrible. I couldn't sit by and let this happen."