A Port Alberni father of a six-year-old boy who died under suspicious circumstances last month says he fought for custody of his son before his untimely death.

Patrick Lucas remembers the last time he spoke with his son, Dontay, on Dec. 18 last year.

"The last words my son said to me were, 'Dad, why can't I come live with you?" the emotional father told CTV Vancouver Island. "Especially those words coming out of my boy: 'I love you dad.' Now I won't be able to hear that anymore."

On March 13, Dontay was found in medical distress inside a Port Alberni home where he lived with his mother.

He was taken to hospital, but did not survive. Two weeks later, RCMP confirmed his death was being investigated as suspicious.

Investigators aren't releasing any further details about what led to the boy's death, and his mother did not want to speak with CTV News when contacted.

Lucas admitted life wasn't easy for his son, who he says was taken from him and the boy's biological mother shortly after he was born and put into a foster home.

"I chose my addictions first and my relationship over my kids back in the day," Lucas said.

He said he was in and out of jail numerous times over the years, but began to turn his life around in 2015.

"I've been 21 months clean off of drugs, about 14-15 months off of the alcohol," he said.

Lucas said since getting sober, he's fought for custody of Dontay over the past year.

"I'm just as lost as everybody else, and now of course we all want answers," he said. "We all want justice for my son."

The Ministry of Children and Families wouldn't say whether it was involved in the incident. B.C.'s children's watchdog said it was monitoring the case, but it was too early to say if it would launch an investigation.

Moved by Dontay's death, one Port Alberni woman has organized a community vigil scheduled for Friday night.

"We just don't want this boy to be forgotten," said Kourtney Brookes. "It's just a way for the community to come for closure, to be able to tell their stories and share what they knew of him…the whole town I think just really needs to come together for closure."

As for Dontay's father, he says closure won't come until investigators conclude what happened to the young boy – and why.