Amanda Knox’s alibi for the murder of the British student Meredith Kercher could now be in doubt after an Italian TV programme released CCTV footage which appears to show her on the night of the killing six and a half years ago.
The American, who was studying in the university city of Perugia at the time, has consistently denied the murder and said there is no evidence placing her at the home she then shared with Ms Kercher.
Yet black and white video footage has now emerged which the investigative programme Quarto Grado said was taken from a nearby security camera and time-stamped 8.53pm on 1 November 2007 - the night of the murder.
The video seems to show a woman wearing jeans and a long coat, similar to those Knox was pictured in during the days following Ms Kercher’s death, in the car park outside the students’ house.
According to The Times, the Italian programme explained that the woman appears on the video just two minutes after Ms Kercher herself, and included a close comparison between the ways she and Knox walk.
Knox has consistently claimed that on the night of the murder she had been staying with her then-boyfriend Raffaele Sollecito, who has also been convicted of the killing by an Italian court.
The pair were found guilty in a joint trial in 2009, acquitted on appeal in 2011 and then once again found guilty in January this year. They are now appealing for a third and final trial, though Knox has refused to return to Italy to attend any more court hearings.
In pictures: The trial of Amanda Knox and Raffaele Sollecito
In pictures: The trial of Amanda Knox and Raffaele Sollecito
1/14 Amanda Knox 's lawyer arriving for the final verdict
Amanda Knox 's lawyer Carlo Dalla Vedova arrives at the Italy's Supreme Court in Rome on March 27, 2015, the day that Knox's verdict was overturned
2/14 Raffaele Sollecito's lawyer before the final verdict
Giulia Bongiorno, lawyer of Raffaele Sollecito, delivers comments at the Palazzo di Giustizia courthouse before the last session for the final verdict of the Amanda Knox and Raffaele Sollecito murder retrial
3/14 Amanda Knox on 'Good Morning America'
Amanda Knox sits alone before being interviewed on the set of ABC's 'Good Morning America' in New York, 2014
4/14 Amanda Knox on 'Good Morning America'
Amanda Knox wipes her nose with a tissue while making a television appearance in New York, 2014
5/14 Amanda Knox on 'Good Morning America'
Robin Roberts interviews Amanda Knox on ABC's 'Good Morning America' in New York, 2014
6/14 Raffaele Sollecito leaves the court
Raffaele Sollecito leaves the court in Florence, 2014
7/14 Raffaele Sollecito leaves the court
Raffaele Sollecito leaves the court in Florence. Judges in a Florence court gathered to decide whether US Amanda Knox and her Italian ex-boyfriend Raffaele Sollecito are guilty of the 2007 murder of British exchange student Meredith Kercher in Perugia, 2014
8/14 Kercher's sister, Stephanie Kercher and brother Lyle Kercher
Kercher's sister, Stephanie Kercher (L) and brother Lyle Kercher speak during a press conference in Florence, 2014
9/14 Appeals Court Judge Alessandro Nencini reads out the verdict
Appeals Court Judge Alessandro Nencini (C) reads out the verdict for the murder of British student Meredith Kercher in Florence, 2014
10/14 Layers of Raffaele Sollecito Luca Maori, Giulia Bongiorno and Amanda Knox's lawyer Carlo Della Vedova
(L-R) Layers of Raffaele Sollecito Luca Maori, Giulia Bongiorno and Amanda Knox's lawyer Carlo Della Vedova attend the final verdict of the Amanda Knox and Raffaele Sollecito retrial at the Courthouse of Florence of Nuovo Palazzo di Giustizia in Florence, 2014
11/14 Amanda Knox on NBC News' 'Today' show
Amanda Knox speaks to Matt Lauer (L) as she appears on NBC News' 'Today' show in New York, 2013
12/14 Amanda Knox at a news conference at Sea-Tac International Airport
Amanda Knox cries and gestures to friends while her mother Edda Mellas sits next to her during a news conference at Sea-Tac International Airport, Washington after Knox landed there on a flight from Italy, 2011
13/14 Amanda Knox leaves the court
Amanda Knox breaking in tears as she leaves the court after the announce of the verdict of her appeal trial in the Meredith Kercher' murder at Perugia's court, 2011
14/14 Amanda Knox and Raffaele Sollecito
Amanda Knox and Raffaele Sollecito stand outside the rented house where 21-year-old British student Meredith Kercher was found dead in Perugia, 2007
Latza Nadeau, an expert on the case and the author of a book inspired by its events, told The Times that while the CCTV footage would clearly not help Knox’s defence case if it is proven to be her, it would not necessarily help the prosecution either.
She told the newspaper: “If the prosecution shows someone like Amanda Knox walking away from the crime scene it's not helpful. For the defence, if there is a video of her anywhere near the house it's not helpful to them because her alibi is that she was at Raffaele's house.”
Last week Knox claimed there was “no logic” to the appeal court in Florence’s decision to reinstate her conviction for the murder.
It issued a 337-page document saying it was Knox who delivered the fatal knife blow to her 21-year-old roommate, adding that her wounds indicate multiple aggressors and that the two exchange students fought over money on the night of Ms Kercher’s death.
In its explanation the appeal court said that a third person convicted of the murder, Rudy Hermann Guede, did not act alone, and cited the nature of the victim's wounds, as well as finger imprints on her body indicating she had been restrained.
The court said it had evidence of a fallout between the two roommates, including statements by Guede under police questioning that Ms Kercher had accused Knox of taking money from her room.
The document said: “It is a matter of fact that at a certain point in the evening events accelerated; the English girl was attacked by Amanda Marie Knox, by Raffaele Sollecito, who was backing up his girlfriend, and by Rudy Hermann Guede, and constrained within her own room.”
It ruled out a previous explanation for motive – a sex game gone wrong – because it was not in Ms Kercher's character.
Guede was convicted in a separate trial of sexually assaulting and stabbing Ms Kercher. His 16-year sentence - reduced on appeal from 30 years - was upheld in 2010 by Italy's highest court, which also said he had not acted alone.
Additional reporting by PA