The Government does not have all the information or analysis it needs to be sure Saudi Arabia is not using British-made weapons for attacks on civilians that could be breach international law, ministers have admitted.

A UN report earlier this year accused Saudi Arabia of “widespread and systematic” attacks on civilian targets, in breach of international law, during its year-old campaign to prop up the Yemeni government in its conflict with rebels from the Houthi movement

Britain is one the main arms suppliers to Saudi Arabia, and the UN report, along with numerous other alleged incidents documented by human rights groups, have led to concerns that weapons made in the UK are being used in attacks on civilians, placing the UK in breach of arms export rules.

The Government has faced calls from Labour to suspend arms sales to the Saudis while investigations take place, but has so far refused to change its export relationship with the regime in Riyadh. Concerns around the sales led MPs to set up an inquiry, led by the Arms Export Controls Committee, which heard its first evidence from ministers on Wednesday.

Appearing before the committee, Foreign Office minister Tobias Ellwood said that Saudi Arabia itself had “an obligation to come forward and make sure all the information is provided”.

“I share the frustration of this committee that that information has been slow in coming forward,” he said. “This is a nation that is not used to sharing information in this manner. It is not used to having to internationally expose the details of what it does. This is the first time it has had to do sustained warfare. It must look up and answer to the international standards that we expect and we will make it very clear if we feel it does not meet those standards.

“But we do require time and Saudi Arabia will require time to provide the analysis that is needed to be done in all these cases,” he said.

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Responding to the committee hearing, Amnesty International UK’s arms control director, Oliver Sprague, said: “Saudi-led attacks on the Yemeni population have been widely-documented, with thousands of civilians killed or injured, and rather than just sitting back and letting Saudi Arabia conduct its own investigation the UK should immediately suspend arms sales before even more civilians are killed.”

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“There’s strong legal evidence that the UK’s weapons sales to Saudi Arabia are not just ill-advised but actually illegal.