Calgary police are looking into a patent dispute as part of their probe into the disappearance of a five-year-old and his grandparents, a source close to the investigation told CBC News. 

Nathan O'Brien and his grandparents, Alvin and Kathy Liknes, were last seen at their home June 29 after hosting an estate sale, and police announced July 14 that they believe all three were murdered even though their bodies have yet to be found.

Douglas Garland

Douglas Garland, who was taken in for questioning from a rural Airdrie, Alta., property on Friday, has a criminal history, including drug trafficking and possession of stolen property after he was caught making amphetamines on his parents' acreage in 1992. (Calgary Herald)

CBC News has learned Winter Petroleum, a junior gas company that was owned by Alvin Liknes, went bankrupt near the end of June — just days before the family went missing. 

Sources say a business deal between Liknes and Douglas Garland, who police initially called a "person of interest" in the case and was later charged with murder in connection with the deaths of the Likneses and their grandson, went sour. The collapse of the business deal led to "bad blood," police said.

Alvin Liknes had previously registered a patent for an apparatus that separates gas from water. Family members confirmed to CBC News that the patent was a sore point between Liknes and Garland, who had worked together in the past.

Police confirmed they are looking into the business relationship between Garland and Liknes. 

"There are some business issues that we are looking into," Calgary Police Service spokesperson Kevin Brookwell said on July 10. "I can't get into specifics about what these are and who was involved, what they look like or how many people were involved. But yes, we have got a number of people who are looking into that." 

Court records also show that both Alvin and Kathy Liknes had declared bankruptcy in the past – Alvin in 1994 and Kathy just two years ago.

According to records, Liknes was involved in several civil lawsuits in the 1980s and early 1990s. He was the defendant in two cases four years ago.

Alvin Liknes's son is in a common-law relationship with Garland’s sister. 

Search expands

In their search for clues in the case, police expanded their search from a rural acreage in Airdrie, north of Calgary to landfill sites in Calgary, police say. 

Emergency vehicles at Garland property

Emergency and police vehicles arrive at the Garland acreage near Airdrie on Wednesday. (Terry Reith)

Police say that evidence in the Liknes home suggests a violent altercation occurred there. 

In what police say is a routine procedure, they asked all three Calgary area landfills to segregate any waste that has come in since the family's disappearance, Brookwell said. 

Search teams moved to the East Calgary Landfill in the city's southeast on the morning of July 10. A day earlier, police began searching the Spyhill Landfill in northwest Calgary.

Until then, the search had been confined to the rural acreage in Airdrie, which belongs to the parents of Garland.  

Acreage was site of 1990s drug lab

Police said they found flammable and dangerous chemicals at the acreage.

Spyhill landfill

Police officers probe the Spyhill landfill site for clues, a move officers described as 'standard procedure.' (Stephanie Rousseau/CBC)

"We don’t know if it’s chemicals that are part of a typical farm operation or chemicals that could be used for something else," Brookwell said. 

"So, until we know what those chemicals are, we can’t say and it’s too early to speculate what those may be or what they be used for."

In 1992, Garland was caught making amphetamines at the acreage. He was charged with drug trafficking, possession of stolen property and identity theft, among other things. 

Garland, 54, had been in custody since July 4 on a charge of identity theft unrelated to the missing family investigation. He faces charges of identity theft and unlawfully possessing a bank card.

He was later released on bail and then re-arrested on July 14 on murder charges.

Community holds vigil for family

Prayer vigil

The O'Brien family attended a prayer service Monday for their missing son, Nathan, and his grandparents. (CBC)

vigil was held the night of July 10 at the Parkhill Community hall, which is just 100 metres from the family's home. 

Police are asking anyone with information about the case, including those who may have been at the estate sale the Likneses held on June 27, 28 and 29, to call the Calgary Police Service at 403-266-1234 or Crime Stoppers anonymously at 1-800-222-8477.