A Romanian man has been arrested on suspicion of assisting unlawful immigration, a Border Force spokesman said.
He added that eight Afghani nationals have also been detained and a criminal investigation has been launched by immigration enforcement officers.
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A "public-spirited" passerby retrieved the child.
A man wanted in connection with a hit-and-run crash which killed a four-year-old girl has been arrested, police have confirmed.
Scotland's First Minister was pictured with her feet up on the sofa while penning the document to Theresa May.