Amanda Knox landed in London and caught a connecting flight home to the United States Tuesday, passing through a VIP area normally used by Queen Elizabeth II, airport officials said.
A day after being acquitted of the murder of British student Meredith Kercher and freed from an Italian jail, Knox touched down at London's Heathrow airport on a British Airways flight from Rome, an airport spokeswoman said.
The 24-year-old American and her family then caught a BA flight to her hometown of Seattle which took off at 0348 NZT, the spokeswoman said.
On arrival at Heathrow, Knox was escorted to the Windsor Suite, a special building away from the main terminal which is normally reserved for royalty, politicians and celebrities, the spokeswoman confirmed.
"It is standard operating procedure for passengers to bypass the terminal area when there is the possibility for disturbance for other passengers, for example when there is media attention," the spokeswoman told AFP.
London's Evening Standard newspaper said the Windsor Suite, whose name references the House of Windsor to which Britain's royal family belong, costs 2,000 (NZ $4,100 ) for passengers to use.
Journalists waiting at Heathrow's Terminal 5 for her arrival were told to leave by airport staff, an AFP reporter said.
BA refused to say if it was making special arrangements for Knox, who was discharged from a jail near Perugia on Monday after her conviction for killing Kercher was overturned.
"We don't discuss the details of individual passengers," a BA spokesman told AFP.
As Knox was leaving Rome, Kercher's family spoke of their disappointment at the fact that the truth of what really happened the night she was killed on November 1, 2007 had been thrown into doubt.
British Prime Minister David Cameron said he felt sympathy for the family.
"Of course I feel for Meredith Kercher's family, because they previously had an explanation about what happened to their daughter and they don't have that any more, and I think all of us should be thinking of them," he said.