Police investigating the disappearance of missing RAF serviceman Corrie McKeague say they will continue searching a landfill site in Cambridgeshire for at least another three weeks.
The 23-year-old vanished following a night out in Bury St Edmunds in September.
Officers have spent the last 10 and a half weeks sifting through more than 3,500 tonnes of waste at the site in Milton, but haven't found any trace of the airman.
However, they say they have have discovered rubbish from Bury St Edmunds that dates back to the same time Corrie went missing.
As this type of search is so unusual, it was not known how the waste would have moved and as the work has progressed officers have gained a greater understanding of both how the waste is deposited and spread out, and the nature and construction of the site. Officers continue to take all of this into account as the search continues.
The work is under constant review and now, in week 11, in view of the dates on items still being found and advice from officers on the ground and the site team, it is likely the search will continue for at least three further weeks to ensure that the area holding waste from the relevant period is comprehensively examined.
Suffolk Police said Corrie's disappearance will now be treated as a cold case as police say there are no "realistic lines of enquiry left".
Suffolk Police said Corrie's disappearance will now be treated as a cold case as there are no "realistic lines of enquiry left to pursue".
Suffolk Police are passing the investigation into the missing airman Corrie McKeague onto a cold case team.