Amanda Knox, whose retrial opens in Italy today for the murder of Meredith Kercher, has received a veiled request not to visit the British exchange student’s grave.

Almost six years after the 21-year-old from Surrey was brutally killed in the university town of Perugia, an Italian court will start hearing a fresh appeal against Ms Knox and Raffaele Sollecito’s convictions for her murder. Ms Knox and Mr Sollecito, 29, were freed on appeal in 2011.

While Ms Knox is not expected to appear at the retrial, she recently said she would like to visit Ms Kercher’s grave. In an interview on ITV1’s Daybreak last week she said: “The greatest closure would be for the Kerchers to take me to Meredith’s grave.”

Download the new Independent Premium app Sharing the full story, not just the headlines

But on Sunday the family of the murdered girl issued a statement saying the body of Ms Kercher is best left in peace. “It took us as a family nearly five years to even begin to feel ready to lay Mez to rest and it is still extremely painful now,” said the statement from her elder sister Stephanie.

“However, she now has a place near to us that we and her friends can visit to take flowers and spend time … Her grave is now her safe place to sleep in peace and be with us and we hope that is respected by all.”

Ms Knox’s trial is the latest step in a tortured legal process that started with the original trial in January 2009 and the pair’s subsequent conviction of the brutal killing. The two defendants will be represented by their lawyers in Florence.

Their retrial came after prosecutors turned to the Supreme Court of Cassation, which cited inconsistencies in the Appeal Court’s reasoning. A fresh trial was ordered in March this year.

“I was very surprised by the appeal verdict acquitting the pair because it was such a complete reversal of the original verdict,” said Professor Renzo Orlandi, a criminal law expert at Bologna University.

Mr Sollecito’s star lawyer Giulia Bongiorno acknowledged after the retrial was announced in March that the Appeal Court may have been “too generous” in ruling that the pair did not commit the crime.

While there remains a weakness of DNA evidence linking them to the scene of the killing, the Supreme Court said it was concerned that the appeal hearing that freed them had failed to take all the evidence into consideration. In October 2011 the senior appeal Judge Claudio Pratillo Hellman lambasted both the weakness of the prosecution’s original case and its treatment of the accused. Ms Knox claimed that bullying and maltreatment by police and prosecutors led her falsely to accuse the bar owner Diya “Patrick” Lumumba of the murder.

In the Italian legal system, a conviction – or an acquittal – is not definitive until it has been issued by the Supreme Court.

Apart from issuing definitive verdicts, the highest legal body also has the power to send back cases to appeal as it has for the Meredith Kercher murder – raising the possibility of a further drawn-out process in the courts. Whatever the verdict in Florence, it is likely to be appealed against again at the Court of Cassation, which could then send it back for another appeal hearing, said Mr Orlandi. “So you could in theory have legal ping pong.”

On Friday, Francesco Maresca, the Kercher family lawyer, said of the fresh appeal: “The hopes are to have a complete, total, neutral and balanced trial which can then lead to a sentence which is properly developed and well-reasoned.”