An international human rights group has called on a company owned by Invest NI to immediately suspend a contract to train security forces in Bahrain.
Reprieve says police and prison officers in the state systematically torture and abuse government opponents.
NI-CO was awarded a £900,000 foreign office contract last year to help reform Bahrain's security forces.
It says the assistance it provides is in line with recommendations from the UN and a Bahrain Commission of Inquiry.
Belfast-based NI-CO (Northern Ireland Co-operation Overseas) is a wholly-owned subsidiary of Invest NI.
Project teams working for the company have been working in Bahrain's security and justice sectors for the past three years.
They have worked with the police and prison services, as well as the office of the Ombudsman, whose job is to investigate allegations of torture.
A Reprieve report says all of those organisations are guilty of systematic abuse.
"The global community, non-governmental organisations (NGOs), the United Nations, other governments, are clear that the human rights situation in Bahrain is dire," said Reprieve's deputy director Harriet McCulloch.
"Bahrain's police are widely reported to be involved in abuse, Bahrain's prisons are widely reported to be the sites of incredibly brutal torture."
Unrest in Bahrain
Bahrain has been racked by unrest since February 2011, when demonstrators occupied Manama's Pearl Roundabout, demanding more democracy and an end to discrimination against the majority Shia Muslim community by the Sunni Muslim royal family.
The government called in the Saudi military to crush protests by demonstrators demanding a greater say in government in early 2011. The Shias claim there is systematic discrimination against them in jobs and services.
Over the years, however, the country enjoyed increasing freedom of expression, and monitors said the human rights situation had improved.
There is no suggestion that NI-CO staff are encouraging such behaviour.
But the Reprieve report says there are concerns that NI-CO has ignored government human rights guidelines, and that its work in Bahrain "deserves urgent attention".
It has called on NI-CO to suspend its work in the country until its government ratifies a United Nations protocol against torture, and allows a UN special rapporteur on torture to visit Bahrain.
It also says Invest NI and the Stormont executive have failed to properly oversee the work of the Belfast based company.
It recommends that the Committee for the Economy at Stormont launches an inquiry into NI-CO's work in the country.
'Abysmal human rights'
In a statement to the BBC, NI-CO said it has worked on behalf of the UK Foreign and Commonwealth Office in Bahrain since 2013.
It said the package of technical assistance is in line with recommendations from the UN and a Commission of Inquiry in Bahrain.
NI-CO said its work is focused on sharing the Northern Ireland experience to strengthen various oversight mechanisms.
Invest NI said that while it is aware of the company's work in Bahrain, it "does not have sight of project-specific detail, nor would it be required to have it".
Invest NI said it was appropriate for NI-CO "to work to support this reform, sharing learnings on how Northern Ireland has dealt with changing attitudes, culture and behaviour".
But Reprieve insists that efforts to reform the security forces in Bahrain have failed.
"This kind of engagement isn't working," said Harriet McCulloch.
"It's engagement that's intended to improve the abysmal human rights situation in Bahrain, and it's not working, and in fact the human rights situation in Bahrain is worsening."