The backlog of 153,000 notifications could potentially have meant that thousands were wrongly allowed to remain in the country, the Chief Inspector of Borders and Immigration said.
The tip-offs were all reviewed by May this year, but Mr Vine said it must be an "ongoing priority" to make sure checks are carried out.
His team examined work at three UKBA offices in Sheffield, Beijing and Delhi.
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According to local reports, the repairman had failed to disconnect the power to the escalator before getting to work.
Millwall fans who caused problems at the match against Barnsley could face lifetime bans, the club said.
Counter-terrorism forces, backed by Shi'ite militias on the ground and coalition airstrikes, are moving into the city on several fronts.