The government is under fire for encouraging British security and defence firms to attend a sales exhibition in the United Arab Emirates sponsored by the Dubai police force, which is accused of torture.

Lawyers from the group Reprieve are working on behalf of Ahmad Zeidan, a 21-year-old British student who was sentenced to nine years in prison for drugs charges in the UAE on the basis of a “confession” given after, they say, being beaten by police officers, hooded, stripped and threatened with rape. They have written to the business secretary, Vince Cable, asking him to explain why his department promoted EmSec, the Emirates Security Exhibition and Conference, which closed this weekend, and ask what checks were made that equipment on sale would not be used for torture. The government’s UK Trade and Investment (UKTI) agency promotes the event on its website and hosted a reception in Dubai during the exhibition.

According to UKTI, “EmSec is a premier platform to showcase technologies and solutions for law enforcement and security markets. Designed to support and encourage UK exports, EmSec is hosted by the Dubai police and includes a conference, demonstrations and one-to-one meetings.”

In her letter to Cable, Clare Algar, executive director of Reprieve, said Zeidan’s case was far from isolated.

“We have worked on behalf of a number of other victims of police torture in UAE – indeed, according to our 2013 survey of Dubai central jail, over three-quarters of prisoners report having been abused following their arrest. Crucially, a significant number of the cases we have worked on report that that torture involved the use of police equipment of the kind that appears to be on sale.”

Algar said there was a wider principle at stake, concerning whether Britain should “be supporting without question the supply of policing equipment to a country known to torture bogus confessions out of people, including in cases where such ‘confessions’ can lead to a death sentence”.

She called on Cable to confirm whether his ministry or UKTI had made an assessment of “whether the equipment being supplied at EmSec could be used for torture or other human rights abuses by UAE police”.

“If so, could you please provide a copy of that assessment?” Algar asked. “And if not, will you commit to immediately carrying out an inquiry into this issue?”

UKTI said: “We take arms export responsibilities very seriously and aim to operate one of the most robust export control systems in the world.

“This government supports a responsible defence and security industry that helps meet the legitimate security needs of other states. We rigorously examine every licence application on a case-by-case basis against the international exporting criteria.”

But Algar described the UK government’s support for the event as “utterly shocking given what we know about the current epidemic of police torture in the UAE.” Licence applications were “rigorously” assessed “on a case-by-case basis”.