Police have found what they believe to be the truck of Tim Bosma, the Ancaster, Ont., man who went missing a week ago today after he posted his truck for sale online.

A black Dodge Ram was found in Vaughan, north of Toronto, at a house belonging to the mother of Dellen Millard, the Toronto man arrested Saturday in connection with the case, police said late Sunday.

The truck was found in a large trailer which, according to neighbours, appeared at the house sometime on Thursday.

Police arrived on the scene at about noon on Sunday. According to witnesses, officers dressed in tactical uniforms opened the trailer at around 3 p.m. ET

They will conduct tests to confirm if it is Bosma’s truck.

Bosma, a 32-year-old father of one who runs a private construction business, went missing May 6. Two men came to take the car posted online for a test drive that evening, and Bosma hasn't been seen since.

Man arrested held world flying record

On Saturday, police announced they had arrested Millard, 27, one of two men last seen with Bosma. Millard has been charged with forcible confinement and theft over $5,000. Police confirmed he was the suspect identified earlier in the week as having an tattoo on his wrist of the word "AMBITION." Investigators are still searching for a second suspect.

A neighbour who lived next door to Millard in the Toronto suburb of Etobicoke confirmed to CBC News his family ran and operated Millard Air, with chartered flights out of Toronto and, more recently, Waterloo. Millard once held the world record for the youngest pilot to take a solo helicopter flight, when he was 14.

Earlier this week, Millard's home was raided by Toronto police, neighbours said. He lived there alone after his father died six months ago. He was last seen by neighbours Wednesday evening working outside on his house with a few other men.

Neighbours also told CBC News they were shocked by the news of Millard's arrest and described him as "a normal kid."

The investigation has taken police across southern Ontario.

Waterloo Regional Police Services confirmed officers were at the Waterloo International Airport both Saturday and Sunday to assist with a Hamilton Police Services investigation. Waterloo police would not confirm the investigation was related to Bosma's disappearance.

"I only know we are at the hangar [that] Hamilton [police were] at. I don't know all the players or names, as this is not our investigation," Waterloo Insp. Kevin Thaler said.

Earlier in the week, Hamilton police asked for the public's assistance in Brantford after receiving reports of Bosma's truck in an industrial park where they also found his cellphone. Police were on scene searching the industrial park on Oak Park Road throughout Friday and Saturday.

Mom makes emotional plea

By Saturday, police reported there were more than 300 tips from the public that were related to their investigation. At one point Sunday morning, the voicemail box for the tipline dedicated to Bosma's case was full due to the high volume of calls received, according to police.

"This is a great community that has rallied in support of finding Tim," Hamilton police Chief Glenn De Caire said Saturday. "In Hamilton, a crime against one is a crime against all."

Bosma’s mother made an emotional Mother's Day plea for his safe return.

"My heart is broken," said Mary Bosma on Sunday.

"We just want him home and on this Mother's Day. It's my prayer and my wish to get my son home with us safe."