A Seattle-area family already struggling with their son's cancer treatment has fallen victim to a cruel hoax that relatives say may have been an attempt by an "obsessed fan" to get close to a celebrity family friend.

Three years ago, Thomas Doty was diagnosed with osteosarcoma, a rare form of bone cancer. The 19-year-old's family went bankrupt paying for his treatments, which included radiation and chemotherapy, as well as several tumor removal surgeries.

Johnathan Hillstrand, captain of the ship "Time Bandit" and star of the Discovery series "Deadliest Catch," is a friend of the family, so he made a video to help raise funds for Doty.

"I've known Tom [Thomas' father] since I moved here to Maple Valley seven or eight years ago," Hillstrand says in the video. "It's just one thing after the next, and they could use a little help," he adds, after explaining some of the family's recent struggles.

According to Q13 Fox, a would-be donor who called herself Johnnica Ellis stepped forward, sending sympathy emails, flowers and promises of $250,000 in aid. Ellis even sent a bank statement claiming that payment was on its way, but the money never came.

When the family tried to contact Ellis, they discovered that her phone and email address had been cancelled. Yet, Ellis would check in periodically with the family, promising money. She also allegedly tried to start a relationship with Hillstrand.

Tiffany Doty, the teen's mother, told the station she believes that the person behind the hoax was an "obsessed fan" who had stolen time from her son and given everyone false hope. "We have lost the last five weeks... with somebody who chose to play games with his life,” she said. “And he doesn't have time for that anymore.”

"I don't understand how someone could be so cruel and heartless, preying on an innocent cancer victim fighting for his life!" the mother wrote on Doty's website under a section labeled "Heartless Hoax."

For more on Thomas Doty, or to help, visit HealThomas.com.

Correction: A previous version of this article misreported Thomas Doty's diagnosis as osteosarcosis. He has osteosarcoma.