A spokeswoman for BAA, which owns Heathrow, said Friday night's long queues, which saw passengers waiting for up to an hour, had cleared by midnight.
Discussing the situation today, she said:
"Everything is looking quite good in the immigration halls. Things are moving and we haven't got major queues.
"The Border Force is putting staff where they are needed at the moment."
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The property developer painted the mews house in March last year after she was denied permission for a basement below the property.
Profits at the estate agent plummeted 42% in the first half of the year.
Ionut Gheorghe, 27, was detained in Los Molinos near Madrid on Friday by Spanish police under a European Arrest Warrant.