Tysen Benz
Tysen Benz, 11, took his life after hearing false reports that his girlfriend had died Facebook

A grieving mother has claimed that her 11-year-old son killed himself after his 13-year-old girlfriend faked her own death as part of a social media prank.

Tysen Benz, 11, died at hospital on Tuesday (4 April), after he was found hanged almost a month ago.

He had started dating a girl in secret after buying a phone without his mother's knowledge.

Now his mother, Katrina Goss from Marquette, Wisconsin, has spoken out to allege that the girlfriend faked her death as a prank with her friends.

She had made it look like she had killed herself, Goss said, and used other friends and their social media accounts to add authenticity.

"So, he believed her and said: 'I'm going to kill myself.' I'm quite angry," Goss said to the New York Post.

"I feel like, yeah, they're young and all that... you're completely knowledgeable of your choices and you know right from wrong. You can make your own choices.

"I don't feel like it should be taken lightly," she said, adding those involved must be held "legally responsible for this horrific prank".

Captain Mike Kohler, of the Marquette Police Department, confirmed an investigation into Tysen's death is underway, but declined to comment directly on Goss' allegations.

Precisely what motivated the prank is unclear, Goss said.

William Saunders, superintendent of Marquette Area Public Schools, said in a statement that it had few details because the incident happened away from school grounds, but that officials were cooperating with investigators.

He also warned that young students need to be careful online.

"Many of us have followed Tysen's mother on social media and agree wholeheartedly in her statements regarding the dangers of social media," Saunders said. "After the gut-wrenching loss of a student we ask ourselves, 'How can we do more?'"

More than $30,000 (£24,000) had been raised by in a GoFundMe campaign created shortly after he was hospitalised.