The impoverished Philippine and Sri Lankan refugees helped the former National Security Agency contractor evade authorities in 2013 by hiding him in their cramped homes after he initiated one of the largest data leaks in US history.
They have spent years hoping the government would recognise their cases and save them from being sent back to their home countries, where they say they were persecuted.
However, immigration authorities rejected their protection claims today saying there were "no substantial grounds" for believing they would be at risk if they went home.
"The decisions are completely unreasonable," their lawyer Robert Tibbo told reporters, saying the procedures had been "manifestly unfair" towards his clients.
The refugees have said previously they were specifically asked about their links to Snowden by Hong Kong authorities.
"We now have less than two weeks to submit appeals before the families are deported," said Tibbo alongside the refugees, who were visibly distressed.
He said there was a risk his clients could be detained and their children placed in government custody.
One of the refugees, Vanessa Rodel from the Philippines, who lives in Hong Kong with her five-year-old daughter, broke down over the news.
"The first thing on my mind is I don't want to be detained and I don't want me and my daughter to separate," she told AFP.
Another of the refugees, Ajith Pushpakumara from Sri Lanka, told AFP the government had "taken his whole life" with the decision.
After leaving his initial Hong Kong hotel bolthole for fear of being discovered, Snowden went underground, fed and looked after by the refugees for around two weeks.
Their stories only emerged late last year.
As well as Rodel and Pushpakumara, the group includes a Sri Lankan couple with two young children.
The adults say they experienced torture and persecution in their own countries and cannot safely return.
Their lawyers and some city legislators have said two of the Sri Lankan refugees have been targeted by agents from their home country who travelled to Hong Kong.
Hong Kong is not a signatory to the UN's refugee convention and does not grant asylum.
However, it is bound by the UN Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment (UNCAT) and considers claims for protection based on those grounds.
It also considers claims based on risk of persecution.
After government screening, claimants found to be at risk of persecution are referred to the UN's refugee agency, which can try to resettle them to a safe third country.
But with fewer than one percent of cases successfully substantiated by city authorities, most refugees live in fear of deportation.
Hong Kong's 11,000 marginalised refugees spend years in limbo, hoping the government will eventually support their claims.
Lawyers for the Snowden refugees separately lodged an asylum petition with the Canadian government in March and called for that process to be expedited Monday.
Human Rights Watch also urged the Canadian government to "intervene swiftly and protect them" following the rejection of their petitions in Hong Kong.
The refugees faced "dire risk if sent back to their countries", said Dinah PoKempner, general counsel at the rights group.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)