Scotland Yard anti-terror officers are to stop a search of woodland linked with the alleged airliners bomb plot amid a dispute over funding.
The police search of Kings Wood has come to an end
Thames Valley Police, which was guarding the woods near High Wycombe, Bucks, had said it might pull the plug over spiralling costs.
The force demanded the Home Office cover the £8m cost.
Plans for either military personnel or fencing to be used to seal the site are understood to have been rejected.
The search operation started after the alleged plot was uncovered in August.
Thames Valley Police are thought to have threatened to "walk away from the scene" if it did not get some financial assistance from the Home Office.
The Home Office said its request was still being considered.
Pension reserves option
It is thought Thames Valley may have to dip into pension fund reserves to ensure the force has enough money to cover any unexpected costs next year, if the Home Office turns down its request for extra funding.
Last month, the local force ended its search of Kings Wood and moved onto the Booker Common area.
Ch Supt Graham Bell, from Thames Valley Police, had described the Kings Wood search as "one of the most intensive large-scale searches I can remember".
The alleged plot sparked a massive security operation at Britain's airports and MI5 raised the attack threat level in the UK to critical - its highest.
The authorities believed the targets were both US and UK airlines flying to all parts of the US.