ABUJA (Reuters) - Nigerian lawmakers on Saturday summoned the attorney general, accountant general, minister of interior and four companies to appear before a committee of parliamentarians over allegations that revenues were withheld from the immigration service.

The companies performed services for the Nigeria Immigration Service (NIS) in public-private partnerships, a committee of lawmakers in the upper chamber of parliament chaired by senator Solomon Adeola were told by the head of the NIS.

The services, provided between 2012 and 2016, included the production of e-passports and expatriate residence permits.

The companies had “contractual agreements to perform some revenue generating service on behalf of the NIS with the company withholding a hefty percentage of revenue that would have accrued to the federal government,” a spokesman for Adeola said.

A statement issued by the committee, which sat on Saturday, said there was a “need to get clarification on this issue from all the parties involved”.

The government officials and companies were summoned to appear before a committee of lawmakers in the Senate, the upper chamber of parliament, on April 6.