The Canadian Border Services Agency is facing a possible lawsuit after a 66-year-old grandmother from the U.S. spent 12 days in custody because guards erroneously thought she had heroin in her vehicle.

Janet Goodin's ordeal began on the evening of April 20, when she was making a routine trip to Manitoba to meet with family and play bingo.

But as the Minnesota resident crossed into Canada, she was stopped and searched by Canadian border guards, Winnipeg-based lawyer Scott Newman told CTV.ca by phone Tuesday.

"She was pulled over by a border officer for secondary inspection. They searched her vehicle and they found a canning jar in the back."

The jar in question contained motor oil left from a recent oil change, but Newman said that a border field test apparently showed traces of heroin.

"For whatever reason, the tests indicated that there was something present when there wasn't," he said. "And on the basis of this faulty test, the RCMP was called and she was detained."

Initially, Goodin was charged with trafficking heroin, possession of heroin with the purpose of trafficking and importation of heroin, Newman said.

But after a thorough RCMP test showed that no narcotics were present, the Crown dropped the charges. But not before Goodin spent 12 days in jail.

Goodin was released May 3.

Newman, who represented Goodin during her Canadian ordeal, said the Minnesota resident is "contemplating" a lawsuit against the CBSA.

"Certainly, a civil lawsuit is one of the options that are available to her. I can't advise at this point if she's going to be taking this step."

But Goodin told The Canadian Press Wednesday that it's unlikely she'll be suing, since she's on a fixed income and can't afford more legal costs.

"An apology would be nice, and I would like to be able to pay back the relative that I borrowed money (for legal fees) from."

Goodin was forced to live in filthy conditions and was subjected to a strip search.

While in custody, bail was set at $5,000 along with a surety of $15,000. While Goodin was able to come up with the money and her daughters offered up their houses as sureties, the homes were rejected because they are on a reserve.

A source at the public safety ministry declined to comment Wednesday and referred any questions to the CBSA.

While CBSA spokeswoman Lisa White declined to comment specifically on the case, she alluded to the field tests that are often used in cases of suspected narcotic trafficking.

"If a field test returns a positive result, then we have probable grounds that the substance is a narcotic," she said.

White said that when such tests show the possibility of drugs, the evidence and the case is turned over to the RCMP.

White wouldn't say if the CBSA was launching an internal review of the case, but she said that all complaints are taken seriously.

Goodin will appear on Canada AM on Thursday morning.