It marks the latest set-back in the eight-year investigation.
We look back at the twists and turns of the agonising, enduring mystery.
March 18 – Claudia last seen on CCTV on her way home from work at the University of York
March 19 – Claudia doesn’t arrive for her 6am shift
March 21 & 22 – Missing Persons appeals released by North Yorkshire Police
March 23 – Press conference held by North Yorkshire Police appealing for information. Claudia’s image is projected at Leeds Railway Station.
May – BBC Crimewatch film a reconstruction of the last sighting of Claudia. The number of visitors to findclaudia.co.uk reaches 10,000.
July – A 26-year-old Selby man is given a conditional discharge and ordered to pay court costs after making a drunken phone call to police claiming he had found the body of Claudia Lawrence under a bush.
August – Police announce £485,000 has been spent by on the investigation so far, including £90,000 in the first 12 days of Claudia’s disappearance.
September – Police search the biology department of the University of York. Tourism workers claim to remember seeing Claudia in Cyprus in Paphos in March.
October – Police announce they will be speaking with former partners of Claudia. Peter Lawrence unveils images of Claudia at Edinburgh’s Waverley Station.
November - Hoax message left on Facebook by a teenager from Oxfordshire, purporting to be from Claudia, saying: “Hi everyone just let you be aware that I am ok and I am safe and sound. Speak to all soon. Claudia. xxx” He is later arrested and cautioned. Cost of investigation so far is £558,000 to North Yorkshire Police.
February – Claudia Lawrence Awareness Day held in St Sampson’s Square by friends and family.
March – Hoax calls start a four-day search in Heslington following the first anniversary of Claudia’s disappearance.
April – TV crew visits The Press for a Channel 4 documentary on Claudia’s disappearance. Claudia’s sister Ali Sims speaks to The Press about the toll the disappearance has taken on the family.
July – Police investigation scaled down from more than 100 officers to 16, then seven, after £770,000 was spent on the case. A house in Thornton-le-Dale is the latest to be searched in connection with the case.
August – Peter Lawrence visits Claudia’s Heworth Road home for the first time since March 20, 2009, and calls it a “strange and numbing experience”.
September – Crimestoppers withdraw the £10,000 reward for information. This is reinstated in October 2010.
December – Peter Lawrence begins supporting Missing People.
January – Peter Lawrence meets MPs at Parliament to support calls to change the law and help families deal with the estates of missing people.
February – A Vigil For The Missing held at York Minster to mark Claudia’s 37th birthday, attended by Kate McCann, the mother of missing child Madeleine McCann.
March – Crimestoppers withdraw the £10,000 reward again.
May – Peter Lawrence addresses racegoers at York Racecourse appealing for information.
December – 1,000 days since Claudia’s disappearance detectives announce a potentially crucial new witness has come forward. Claudia’s family urge whoever is leaving wreaths at her home each Christmas to stop doing so.
January – Police investigate a hole in woodland in Heslington Lane near the University of York.
February - Peter Lawrence again addresses MPs on changing the laws to make it easier for the families of missing people to deal with their estates. An overhaul of Facebook causes thousands of messages of support to be lost from a page supporting the investigation.
March – Another Crimewatch appeal for information on the third anniversary of Claudia’s disappearance.
October – Peter Lawrence is presented with a Special Achievement Award at The Press Community Pride Awards. He also appeals again to MPs at Parliament.
December – Missing People Northern Carol Service held at St Chad’s Church. Joan Lawrence claims chances were missed by the initial police investigation into Claudia’s disappearance.
January – Remains of a woman, later revealed to be Lisette Dugmore, found by the River Ouse. Det Supt Ray Galloway retires from North Yorkshire Police, but maintains the investigation into Claudia’s disappearance will continue.
March – A national Sunday newspaper claims Claudia was planning a new life in Cyprus prior to her disappearance. ‘Gone’, a book detailing Claudia’s disappearance and the subsequent investigation, is released by author Neil Root.
July – North Yorkshire Police announce the Major Crime Unit will review the investigation into Claudia’s disappearance.
September – Rodney Ballard, 66, of Nottingham, is reported to police for harassment of the Lawrence family. He claims to be a psychic, posted a sketch of the moment he claims Claudia was murdered on his website, and was allegedly responsible for laying a wreath at her home each Christmas.He was arrested in December 2013 after breaching an harrassment order.
October – Forensic officers begin a new search at Claudia’s Heworth Road home, in a search which lasts several weeks.
December – Peter Lawrence and Claudia’s friend Suzy Cooper speak at the Missing People Carol Service.
February – Claudia’s 40th birthday.
March – Fifth anniversary of Claudia’s disappearance. Claudia's dad Peter speaks of his new hope
Police reveal fresh leads in the investigation.
July - A 46-year-old man is arrested on suspicion of perverting the course of justice. He is released from bail without charge in April 2015.
September - Peter Lawrence marks 2,000 days since Claudia disappeared
January - Daniel Oxley, 22, is jailed for life for murdering a man in County Durham. During his arrest, he claimed to have murdered Claudia. His barrister said Oxley "said attention-seeking and grandiose things after he was arrested to those in authority to misrepresent his own position".
February - Detectives say more arrests expected, and a search is carried out of the alleyway behind Claudia's Heworth home. Det Supt Malyn said "I know people have lied to us", but he remained determined to resolve the investigation. The search finds "nothing of significance".
March - A man in his fifties is arrested on suspicion of Claudia's murder. Police release new CCTV and display it on a big screen close to Claudia's Heworth home. Changes to the Guardianship law to help families of missing people are agreed by Parliament, but more than 12 months later have yet to be introduced.
April - Three men in their fifties are arrested on suspicion of Claudia's murder, and three properties in the Heworth area are searched by police. Joan Lawrence is interviewed by the BBC and says she still writes to Claudia, and hopes she will one day read the letters.
May - North Yorkshire Police announce Operation Essence has so far cost about £400,000, taking the full cost of the investigation into Claudia's disappearance to well over £1m.
September - The four men arrested on suspicion of murder are all released from bail. North Yorkshire Police say their files will be presented to the Crown Prosecution Service, who will determine how the investigation should proceed, and whether any charges should be brought.
November - A documentary by Donal McIntyre looks again at the investigation into Claudia's disappearance.
December - Joan Lawrence releases new photos from her family album showing Claudia as a young girl, ahead of a special service in her memory.
March - Peter Lawrence appears at Parliament calling for the changes to the guardianship laws to be brought before the House.
January - Claudia's Law passes its first reading in the House of Commons, but Operation Essence begins to be scaled back.