The three people jailed after 23 Chinese cockle pickers drowned in Morecambe Bay ten years ago have all been deported back to China.
Gangmaster Lin Liang Ren, now 39, was jailed for 14 years at Preston Crown Court but was released in 2012 after serving around than half - around four months for each life lost.
Details have only just come to light and the Parole Board is remaining tight lipped about his release.
Ren’s girlfriend Zhao Xiao Qing, now 31, and cousin Lin Mu Yong, now 41, formerly from Liverpool, were released in 2007 and 2008 respectively, the Home Office confirmed.
Zhao Xiao Qing and Lin Mu Yong were found guilty of helping people breach immigration law and Ren and Qing were found guilty of three charges of perverting the course of justice.
Lin Liang Ren was convicted of 21 counts of manslaughter in 2006 – two years after a group of Chinese workers cockling in Morecambe Bay perished in a tragedy that shocked the world.
Ren was a heavy gambler who had callously planned a night out in casinos in Blackpool and Southport while his exploited workers were out in the Bay in freezing temperatures.
David Morris, MP for Morecambe and Lunesdale, said: “My personal view is he should have served the full 14 years. Currently his time he served equates to around four months for each life lost.
“I have asked Parliamentary questions about what has happened to the people responsible, where they are now and if they are in custody in China.”
London lawyer David Tang, who represented the surviving children and families of the tragic workers, said: “I did not know about this man’s (Ren’s) release.
“However, a bid made to the Criminal Injuries Compensation Scheme some years ago failed because the workers were not here legally.”
The Home Office refused to comment on individual cases but a spokesman said: “It is usual for a person to be released at the half way point of their sentence and any time spent on remand to be taken off.”