An Ontario family has learned that their 24-year-old son, who they thought was teaching English overseas, has been killed in Syria while fighting against Islamic State militants.

Nazzareno Tassone was fighting alongside Kurdish forces when he was killed in the city of Raqqa on Dec. 21, according to a letter the Kurdish People's Defense Units sent his family.

Tassone's younger sister said the letter was delivered to her mother's Niagara Falls, Ont., home by police and members of the Toronto Kurdish community on Tuesday.

"It was a bomb drop," Giustina Tassone told The Canadian Press. "We weren't too sure what really to do, there was a lot of tears."

The letter, which did not contain specific details of her brother's death, said his body had been taken by Islamic State militants, she said.

The Kurdish group called him in the letter a "daring and courageous companion" and an example for younger fighters, she said.

Nazzareno Tassone grew up in Keswick, Ont., but had been living in Edmonton earlier last year and was working as a security guard, his sister said.

In June, he decided to leave Canada, telling his family he was headed to Iraq and Turkey to teach English, she said.

"We didn't have full knowledge of what he was doing," she said, adding that the family suspected he was going there to fight in the war "because that's what my brother always wanted to do."

Tassone's sister and mother last saw him at Toronto's Pearson airport before he left, his sister said. Once he was in the Middle East, he only had intermittent Internet access but used to send his mother the occasional Facebook message to let her know he was fine.

In early July, Tassone posted a message on Facebook saying "Internet will cut out soon so if I disappear again, don't worry....just the Middle East." A few days later he posted "still alive."

Tassone had been interested in the military from a young age and had tried to join the Canadian Forces but had a chest condition and his application was denied, his sister said.

"My brother was very involved in the military news kind of thing and he always had an opinion on something," she said. "This was just my brother fighting for what was right."

He was a wonderful sibling, Giustina Tassone said.

"My brother may have loved all things military but he was a goofball," she said. "We would play video games, we would joke around...we were those kids who broke the couches from jumping on them."

The family is now hoping the Canadian government can help recover his body so it can be brought back to Ontario for a funeral.

"We need to bring him home," his sister said.

A Global Affairs spokeswoman said Canadians who travel to Syria and Iraq do so at their own personal risk.

"Due to the unpredictable security situation, the Government of Canada's ability to provide consular assistance in all parts of Iraq and Syria is severely limited," Kristine Racicot said in an email. "That being said, we will do our best to assist the family through this difficult time."