One of the men who built an underground "man cave" that raised concerns about a possible terror plot north of Toronto says he built it as a "dream" project.

Elton McDonald, a 22-year-old construction worker, spoke to NewsTalk 1010 radio host Joe Warmington, and said he was behind the tunnel's construction. Sources confirm to CP24 that McDonald is the man who built the tunnel.

McDonald told Warmington he began digging the 10 metre long, 2-metre high tunnel two years ago with friends, just because it had always been something he wanted to do.

According to a report on the interview published in the Toronto Sun, McDonald said he chose the spot simply because his parents live near the property. He said he didn't even realize he was so close to the Rexall Centre, where the Pan Am Games tennis competition is slated to take place this summer.

McDonald said it took about five months to excavate the underground space, which was held up with wood beams and plywood.

But after he experienced a serious wall collapse during the construction, he hung up a poppy on the wall, along with a rosary his sister had given him, for "good luck, a prayer."

The underground bunker was discovered in mid-January, under a wooden trap door buried in dirt. With fears that the tunnel might be used to plan a terror attack or for some other criminal intent, Toronto police issued a call to the public asking for their help in identifying the tunnel's builders.

After the tunnel made headlines around the world, McDonald told Warmington he was too nervous to come forward. In the end, it was police who found him, after tracing the generator back to the construction company where McDonald works.

Police announced earlier this week they had determined who built the tunnel and were satisfied it was not being used for criminal purposes, but for "personal reasons."

They said they would not be identifying the tunnel builders because no charges were being laid.

After investigating the tunnel for several weeks, police eventually filled it back in.