A minister has denied reports that an estimated 300,000 visas giving foreigners to the right to come to Britain may have been wrongly approved every year.
The figure emerged after the independent visa monitor, Linda Costelloe-Baker, gave evidence to MPs on Tuesday.
She told the Commons home affairs committee that consulates and embassies examine 2.4 million visa applications a year from tourists, business people and those visiting relatives.
Checks are made to the accuracy of all application rejections, she said, but no similar system was in place to check those applications that were approved.
She was asked by Conservative MP David Davies if it was reasonable to assume that, if 15 per cent of rejections were found to be incorrect, a similar proportion of approvals were "incorrectly approved".
"I think that's a reasonable supposition," Costelloe-Baker said, adding that the total would include cases where an applicant rightly got a visa but where there were errors in the way the visa was approved.
Immigration minister Phil Woolas, giving evidence to the same committee on Thursday, said Costelloe-Baker had written to the home secretary to confirm categorically she "did not say that 300,000 visas were wrongly issued".
Woolas said: "Indeed on reading about the evidence I checked the formal reports of the independent monitor, which show that under one per cent in her estimation of refusals were issued by mistake."
Costelloe-Baker had been trying to help the committee understand how the visa process worked, he said.
The independent monitor covers refusals, not acceptances, he added, "so it was not possible to have an evidence base from the independent monitor on acceptances of visas".
"There are other systems in place to ensure the robustness of those decisions," he said.
"The evidence from the independent monitor's report and from what she gave to the committee is that within some of the refusals there will be errors in the process which does not mean that the decision was wrong.
"Some of the errors may be spelling mistakes, or misquoting a particular piece of legislation."
He went on: "So I can reassure you that it is not the case that 300,000 visas have been issued wrongly."
Dods Parliamentary Communications Ltd