Three of the four men accused of bringing hundreds of Tamil migrants into Canada illegally have been found not guilty by a jury in B.C. Supreme Court.

Justice William Ehrcke declared a mistrial for the fourth man after a jury told the court it couldn't reach a verdict in the case of Kunarobinson Christhurajah.

Lesly Emmanuel, Nadarajah Mahendran and Thampeernayagam Rajaratnam were acquitted by the jury after their

lawyers argued they had acted on humanitarian grounds or had been misidentified.

"It's great," Emmanuel said outside court, grinning. "It's beyond words."

Speaking outside court, Mahendran's lawyer, Mark Nohra, said he wasn't surprised by the verdict given the many problems that plagued the RCMP's investigation into his client, which he highlighted for the jury during the trial.

"I felt that there were so many problems with how things were done that the jury would see that," Nohra said. "And I think they did see that."

The jury began its deliberations last Thursday, but on Wednesday told the judge they were collectively exhausted and couldn't reach a verdict.

"The jury has made a great deal of progress over the last week. However, consensus continues to elude us on some key points," they told the judge in a note. "You will be unsurprised to discover that these are the most difficult and emotional points to discuss."

Ehrcke told jury members to go back and determine if they could reach any verdicts, and if they couldn't he would declare a mistrial. They returned minutes later with the three not guilty verdicts.

The Crown declined comment outside court.

6-year ordeal

The MV Sun Sea travelled from Thailand to Canada in the summer of 2010 carrying 492 Sri Lankan Tamils who intended to claim refugee status.

Christhurajah and Emmanuel are Sri Lankan nationals, while Mahendran and Rajaratnam are Canadian citizens.

The court heard how the derelict cargo ship, which was considered unseaworthy in the open ocean, crossed the Pacific without the assistance of a formal crew.

During the trial, lawyers for Christhurajah, Emmanuel and Rajaratnam argued their clients acted for humanitarian reasons, either to assist their family members or to help fellow asylum seekers.

Emmanuel's lawyer said his client bought a ticket intending to be a passenger on the vessel. It was only after the Thai crew abandoned the ship that Emmanuel was pressured into taking over as captain because of his maritime experience, his lawyer said.

Christhurajah was an asylum seeker and travelled on the Sun Sea with his wife, while Rajaratnam's mother-in-law, father-in-law, brother-in-law and two cousins were on board, the court heard.

Mahendran and Rajaratnam were in Canada at the time of the ocean crossing in 2010, but the Crown argued both had travelled to Thailand earlier to help arrange the voyage.

Mahendran's lawyer told the court his client was a victim of misidentification. He said the witness testimony condemning him was collected by the RCMP and Canada Border Services Agency in a "deeply flawed" manner that broke "almost every single rule" designed to prevent wrongful conviction.

He said those mistakes included leaving identifying numbers on pictures used in a photo lineup, allowing migrants to discuss the pictures and officers giving supportive feedback, such as saying "good job."

In a 2015 judgment linked to the MV Sun Sea, the Supreme Court of Canada ruled that the country's human smuggling laws were too broad, and that people could not be found guilty for acting on humanitarian grounds, helping family members or assisting fellow migrants.