An Italian court's decision on whether to uphold the convictions of Amanda Knox and Raffaele Sollecito for the murder of Coulsdon student Meredith Kercher is due to be made today, court officials said.

Italy's highest court had been expected to reach its decision on Wednesday but closing arguments took longer than expected.

Ms Kercher, 21, was sexually assaulted and stabbed to death in her bedroom in 2007 while studying in Perugia, Italy.

Her flatmate Knox, a student from Seattle in the US, and Knox's then-boyfriend Sollecito spent four years in jail for the murder but were acquitted on appeal in 2011.

Knox returned to the US before an appeal court threw out the acquittal and reinstated her and Sollecito's guilty verdicts last year.

Italy's Supreme Court in Rome must decide if it finally upholds those convictions, which would put an end to eight years of courtroom twists and turns, or orders another appeal.

A spokeswoman for the court said: "The public hearing will continue at 9am, when one of the lawyers of the appeal will intervene.

“The panel of judges will go into chambers and then deliver their verdicts."

Knox, who is now 27, will not in court to see if her 28-year sentence is confirmed.

Sollecito, 30, who has had his travel documents seized, has been mobbed by journalists and camera crews as he made his way into the Palace of Justice in central Rome. He faces a sentence of 25 years.

The Kercher family were not in court on Wednesday but have said that if Knox's conviction is confirmed they want authorities in the US to extradite her to Italy.

Kercher family lawyer Francesco Maresca said earlier this week: "The interest of the family is to arrive to the end of this trial. They want to be able to remember Meredith outside of the court room."

Knox said last year she would become a "fugitive" if convicted and would have to be taken back "kicking and screaming" to Italy.

If her conviction is upheld she could delay going to jail if she were pregnant, according to Italian legal experts.

Last month, she announced her engagement to 27-year-old musician and school friend Colin Sutherland, who wrote to her while she was in jail.

There has also been speculation that political pressure from the US could hamper the extradition process.

Sollecito is reportedly seeking to separate his case from Knox's, with his lawyers pointing out that a partial confession written by the American and later retracted did not mention his presence at the scene of the crime.

If that argument succeeds, the Italian could be given a new trial.