The European Commission is refusing to publish the findings of a human rights inquiry into Tunisia it conducted shortly before announcing a controversial migration deal with the increasingly authoritarian north African country.

An investigation by the EU ombudsman found that the commission quietly carried out a “risk management exercise” into human rights concerns in Tunisia but will not disclose its results.

Until now, Brussels has repeatedly stated there was no need for a human rights impact assessment into last year’s deeply contentious deal that has been linked to myriad abuse allegations.

“The ombudsman found that, despite repeated claims by the commission that there was no need for a prior HRIA [human rights impact assessment], it had in fact completed a risk management exercise for Tunisia before the [deal] was signed,” the watchdog said in a report published on Wednesday.

Unveiled in July 2023, the €150m (£125m) EU-Tunisia migration pact is aimed at preventing people from reaching Europe and was announced amid concerns that the north African state was increasingly repressive and its police operated largely with impunity.

A Guardian investigation last month revealed abuses by EU-funded security forces in Tunisia, including allegations that members of the Tunisian national guard were raping migrant women and beating children.

Days later, evidence was passed to the international criminal court (ICC) chronicling widespread abuse of sub-Saharan migrants by the Tunisian authorities.

The situation is unlikely to have improved since then, with the re-election of Tunisia’s autocratic president, Kais Saied, who has a record of racist tirades against migrants from sub-Saharan Africa.

The ombudsman, Emily O’Reilly, in her report admonished the European Commission for withholding what it knew about human rights abuses before announcing the deal, saying it should have been “more transparent”.

O’Reilly added that carrying out an explicit human rights impact assessment would have been “preferable” because they were normally made public.

Other areas of concern identified by O’Reilly, a former journalist, include what processes were in place to suspend or review funding when human rights violations were linked to EU funding. She urged “concrete criteria” to be agreed for when EU funding would be suspended to projects in Tunisia owing to human rights violations.

Earlier this month, the Guardian revealed that the EU was unable to claw back any of the €150m (£125m) paid to Tunisia in the migration deal despite the money being linked to human rights abuses.

O’Reilly also wants organisations monitoring human rights in Tunisia to set up complaint mechanisms whereby individuals can report alleged violations linked to EU-funded projects.

Responding to the watchdog, the commission said its “risk management exercise” into human rights abuses in Tunisia was something it conducted with all partner countries that might receive EU budget support.

It added that the exercise took into account criteria similar to those in a normal HRIA, including “human rights, democracy, the rule of law, security and conflict in the relevant partner country”.

“The commission has, however, not proactively shared this information, including in its reply to the ombudsman’s strategic initiative on this matter,” said the report.

A commission spokesperson said: “The EU is a strong promoter and strongly advocates for the respect of human rights across the world, including in Tunisia.

“The commission takes note of the decision and suggestions for improvement of the European ombudsman and reiterates its full commitment to transparency and accountability.”

They added that its approach towards a “human-rights based approach to migration management” was in accordance with its obligations under international law.