As the parents of a missing Montreal man ramped up search and rescue efforts in Peru, they also marked his 23rd birthday on Thursday.

Jesse Galganov has been missing since late September while on a solo backpacking trip in Huarrez, Peru, where he went to hike the famous Santa Cruz trail. His parents, Alisa Clamen and Todd Galganov, travelled to Peru to help look for their son, but Clamen has since returned home and spoke with CTV’s Denise Roberts on Thursday.

“No stone unturned. We will continue this until we find Jesse and bring him home,” she said in an emotional phone interview. “Every minute of every day my thoughts are with my son whose birthday is today.”

The search efforts have been exhaustive since late last year when Clamen hired Magnus International Search and Rescue, an Israeli company known for finding missing persons around the world. But the search has turned up few clues to his whereabouts. After spending much of December analyzing data, the search team returned to Peru last month to continue their efforts. They heard from two French hikers reported to have camped with Galganov on Sept. 30, and another French national who says they saw Jesse walking up the Punta Union pass. The team is currently looking for four Americans who they believe crossed paths with Galganov on his travels, as well as a muleteer who may have seen him on the trails. The investigation has lead the team to speculate whether there may be a criminal explanation for his disappearance.

“I believe if Jesse was there somewhere visible they would have found him. But the fact that he’s not indicates that there is definitely foul play and someone was involved in something,” said Clamen. “There’s no way of knowing who saw him. The only way to do this is meticulously going through and just figuring out how to contact anybody who was there.”

News of Galganov’s disappearance spread across social media last year through targeted PR campaigns using Facebook and Instagram ads. The family also launched online crowdfunding campaigns to help bolster search efforts. A GoFundMe page has accrued over $180,000 in donations at time of writing, and a similar campaign on CanadaHelps.org has also helped, said Clamen.

The family has spent more than a million dollars funding search-and-rescue efforts.

“There’s no choice,” said Clamen. “You would do anything that you could do, and you would spend anything that you had to spend, because there cannot be no answer. There will be an answer and I will bring him home no matter what.”

The parents are holding out hope that their 23-year-old son is still alive, but they have been preparing for the worst after more than four months. "I have to be realistic and I have to keep looking for him no matter the result," Clamen told the Canadian Press in December. "And if something happened and he's out there and not alive, I still have to bring him home."

Jesse was expected to return home in May and his father Todd Galganov says the family is still hoping they will find him.

“He's out there somewhere. Let's find him. Let’s bring him home. I can't keep going all my life, and my son is never found,” he said.

Anyone with information is asked to contact the dedicated email account HelpUsFindJesse@gmail.com. The family is offering a $30,000 reward for information that leads to his whereabouts.

With files from CTV News Montreal’s Denise Roberts.