Canadian border officials have confirmed that they consider the cargo ship that arrived in B.C. carrying more than 450 migrants from Sri Lanka to be a case of human smuggling.

At a press conference Saturday afternoon, Rob Johnston of the Canada Border Services Agency said that conditions onboard the MV Sun Sea indicate smuggling.

"I believe we're dealing with human smuggling in this instance," Johnston told reporters.

He said that the ship had been modified with tarps to extend the living area and maximize the number of people onboard.

"It was very, very cramped conditions," Johnston said. "I don't think anyone would want to be in a ship in those conditions."

But he also described the ship to be "relatively clean and organized," with systems in place to dispose of waste and garbage. The passengers slept in hammocks, and the men were separated from the women and children.

"The migrants were calm, compliant and generally in good spirits," Johnston said.

The CBSA has completed initial processing of more than 350 men, 50 women and 50 children so far, but Johnston said a final number of migrants onboard the ship won't be available until Monday.

He would not comment on the number of unaccompanied children onboard the ship, but said that two pregnant women were among the passengers.

The migrants are in the process of being transported to detention centres in the Lower Mainland, Johnston said.

"Where possible, mothers and children will be housed together," he added. Some children have been taken into the care of the provincial government.

Johnston said that he expects detention reviews for all the migrants to begin next week.

No weapons, communicable disease onboard

Insp. Tracey Rook of the RCMP said that police investigators are currently collecting evidence of criminal offences onboard the ship -- particularly human smuggling.

She said that police are trying to piece together what roles each person on the ship played in the suspected human smuggling operation.

"That is the key focus of our investigation," Rook said.

She added that police have searched the boat up and down and from stern to bow, and have found no weapons.

The Public Health Agency of Canada's Dr. Peter Uhtoff said that environmental health inspectors have not uncovered any evidence of communicable disease among the migrants, although they are still poring over the physical contents of the ship.

Twenty-seven of the boat's passengers were taken to Victoria General Hospital after the ship arrived in Esquimalt Friday morning, but most have since been discharged, according to Dr. Richard Crow, chief medical officer for the Vancouver Island Health Authority.

"Their overall health appears good, considering the circumstances," he said. "There were no indications of active communicable diseases."

He added that most of the patients were treated for nausea, vomiting or dehydration.

Four adults and two children remain in the hospital, although Crow said they could be discharged today.

What is human smuggling?

According to the Ministry of Foreign Affairs, "human smuggling is a business transaction between two willing parties involving movement across borders, usually by illegal means."

Smuggling is different from human trafficking, in which the person being transported is coerced using threats, force or fraud for the purpose of exploitation.