A UK-based human rights organisation has raised concern over the "unsolved murder case" of journalist-couple Sagar Sarowar and Meherun Runi.

The two journalists were murdered brutally inside their apartment in the Raja Bazar area of Dhaka in front of their five-year-old son, Megh, on February 11, 2012.

ARTICLE 19 that works for the freedom of expression and right to information (RTI), on Friday called for taking progressive steps to complete the investigation in the case and bring justice without any further delay.

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“This unsolved case is a shameful example of the strong existence of a culture of impunity that questions the judiciary system of the country where the killers go free. It indicates the failure of the state in protecting the journalists and ensuring the security of the journalists of the country and bringing justice to any disorder," said Faruq Faisel, the regional director, ARTICLE 19.

“No progress of investigation into this murder case clearly threatens the safety of journalists, challenges the state’s protection mechanism and evidentially letting the perpetrators go free makes the government unaccountable,” he added.