People helping undocumented migrants enter Canada by steering the ship or acting as a lookout cannot automatically be branded as human smugglers, the Supreme Court of Canada has ruled.

In one of two related judgments Friday, the court ruled in favour of several Tamils who arrived in B.C. aboard a rickety boat called the MV Sun Sea.

The court called Canada's human smuggling laws "overbroad," saying it would lump in family members and humanitarians helping people seek asylum in Canada.

"The scope is overbroad and interferes with conduct that bears to connection to [people smuggling]," it says on page 4 of the 31-page ruling.

Reaction to the ruling was swift.

Michael Bossin, lawyer for Amnesty International in Ottawa, said in referring to the previous ruling Conservatives: "The Harper government argued that the law should apply to anyone who brings anyone into Canada for any reason, humanitarian or otherwise. Well that decision didn't appeal to the Supreme Court of Canada. They've said no, in fact that is not what the law is all about."

Refugee law has become less human

Laura Track, staff lawyer at the B.C. Civil Liberties Association, said: "Refugee law has become much more punitive and less humane over the past 10 years. There are many aspects of Canadian refugee law that need fixing, and today the court has just fixed just one of them."

In the two separate but related rulings, the top court found unanimously that two sections of the Immigration and Refugee Protection Act do not apply to some people who help refugee claimants reach Canada.

The exceptions include family members, humanitarian workers and migrants helping other migrants.

The cases before the court involved several people accused of human smuggling. Most are Tamils who arrived aboard the MV Ocean Lady and the MV Sun Sea off the B.C. coast in 2009 and 2010.

 'A father offering a blanket to a shivering child, or friends sharing food aboard a migrant vessel, could be subject to prosecution.' - Beverley McLachlin, Supreme Court of Canada chief justice

The court did not strike down the sections of the law dealing with human smuggling, but imposed a narrower definition.

In the case of the migrants aboard the MV Sun Sea, they will now have their admissibility to Canada reconsidered, and if it's granted, will likely file refugee claims here.

In the case of four migrants who arrived via the Ocean Lady, the Supreme Court ruled they will still face a criminal trial based on charges that they took money to bring people to Canada.

Refugee advocates have long argued the law could unfairly label both refugees and humanitarian workers as criminals.

Chief Justice Beverley McLachlin agreed, writing that under the Crown's interpretation of the law, "a father offering a blanket to a shivering child, or friends sharing food aboard a migrant vessel, could be subject to prosecution," something the court ruled as being incompatible with the law's goal.

Legal arguments at issue

At issue in the cases was how strictly the Immigration and Refugee Board should interpret legislation that denies refugee status to anybody who "knowingly organize, induce, aid or abet the coming into Canada of one or more persons" without documentation.

Two of the refugees in question had taken part in some way in the operation of the MV Sun Sea vessel during the voyage, with one working as a cook and another navigating the ship after the original Thai crew left the vessel. A third was a woman deemed inadmissible because she was the wife of on of the first two mentioned.

Previously, two Federal Court judges ruled in favour of the migrants.

Judge Richard Mosley disagreed with defining would-be refugees as people smugglers if they "did not plan or agree to carry out the scheme and have no prospect of a reward other than a modest improvement in their living conditions en route."

Canadian authorities intercepted the MV Sun Sea off B.C.'s coast after it made a three-month voyage from Thailand to Canada. The 492 passengers claimed refugee status due to the armed conflict between the Sri Lankan government and Tamil fighters.

The ship arrived in Canada following after another ship, the MV Ocean Lady, arrived with 76 people in October 2009.

The two arrivals put seaborne refugees in the spotlight and prompted then Prime Minister Stephen Harper to announce a crackdown on human smuggling.

With files from Louise Elliott and Canadian Press