For comparison purposes here are the facts of the police search for April Jones
INVESTIGATION FACTFILE
More than 650 areas around Machynlleth covering 60 sq km were searched
An average of 16 search teams - a total of 150 officers a day - were involved, as well as 10 police dogs, 100 mountain rescuers, two RNLI vessels, kayakers and helicopter support
Dyfed-Powys Police received 4,744 calls and messages from the public
Of these, 2,159 needed follow ups as lines of inquiry by officers
Detailed forensic examination of 27 scenes
29 child witnesses spoken to
Police visited 700 homes during house-to-house inquiries
2,000 hours of CCTV evidence viewed
Dyfed-Powys received help from 45 UK police forces
Police took 1,018 written statements and seized 2,918 exhibits
The force's Twitter following rose from 2,400 to 12,500 in a week; the website's traffic rose fivefold to 100,000 unique visitors a week
The search officially ran from 1 October 2012 to 19 April 2013
Official estimates have put the bill for searching for the missing schoolgirl at £2.4m
Source: Dyfed-Powys Police