There is "no suggestion that Mark Harper knowingly employed an illegal immigrant", Downing Street have said.
The Immigration Minister has announced his resigned over the issue.
Number 10 said David Cameron had "accepted his resignation with regret".
More top news
This afternoon it'll gradually brighten up across many parts of the UK.
Thirty US military cadets have been injured during an annual mass pillow fight by freshmen.
A teenage boy has been stabbed to death in London, the second fatal attack within two days.