Kenyan MPs are investigating the recent recruitment of tax revenue workers after it emerged that some applicants were rejected after doing HIV and pregnancy tests.

The Kenya Revenue Authority (KRA) said it had disqualified 133 job applicants after they did the tests last year.

They were set to undergo paramilitary training to prepare them for their roles as tax collection enforcers.

Kenyan law prohibits discrimination in hiring based on health status.

The news that recruits had been subjected to medical tests visibly shocked and angered MPs when it was revealed in a parliamentary session on Thursday.

"There is no doubt that gross violation of rights has been committed in the recruitment," said Mandera West MP Adan Haji, who chairs the National Cohesion and Equal Opportunity committee.

"Just accept that you have grossly violated over 20 Articles of the constitution and the relevant laws on human rights," he told senior KRA officials.

The tests were defended by KRA commissioner for domestic taxes Rispah Simiyu, who said the Kenya Defence Forces (KDF), which conducted paramilitary training on the 1,406 revenue service assistants (RSAs) "always subject recruits to HIV/AIDs and pregnancy tests".

"The RSA has a dimension of paramilitary training, which requires physical fitness and protection of life during training," Ms Simiyu said. "This approach was purely anchored on health and safety for this group of persons to help maintain training readiness and reduce risk to potential recruits."

KRA commissioner-general Humphrey Wattanga told the committee that the 133 results were confidential and denied discriminating against people based on their HIV/Aids status.

The MPs, however, demanded to know why the job hunters were rejected given that the law prohibits discrimination in recruitment based on health status.

The legislators dismissed the explanation by revenue officials, saying that not all paramilitary training requires HIV tests. They also questioned the role of the military in the recruitment.

The MPs vowed to open a full-scale inquiry.

"This matter needs time, but before that, KRA should explain why we should not force them to hire the 133 with immediate effect," said Kasipul MP Ong'ondo Were.

Teso North MP Oku Kaunya called for "an in-depth probe into the operations of KRA so that our resolutions and proposals will serve as an example to other organizations".

This comes barely two weeks after the High Court nullified the recruitment of all 1,406 revenue workers because it was skewed in favour of two communities.

The court ruled that recruitment was unconstitutional since it picked the majority of recruits from the president's and deputy president's ethnic groups.

The KRA's explanation that there was a higher number of applications from the two communities was not supported by statistics, the court ruled.

The recruitment is part of the government's efforts to increase revenue collection and weed out tax evaders.