Residents of a village have been left baffled by large rolls of £20 notes - normally adding up to around £2,000 - which keep appearing in plain site.
12 bundles have so far surfaced and been handed to police since 2014 - four of them this year.
Officers say they have no idea where the money is coming from but have thanked people for their honesty in handing the bundles in, reports TeessideLive .
The money has been appearing in Blackhall Colliery, north of Hartlepool in County Durham and the most recent was found on Monday.
The money always appears in a different, obvious location.
Detective Constable John Forster said officers had interviewed people and organisations in the village as well as carrying out checks with the local bank and post office and even tested for fingerprints, but the circumstances surrounding the bundles of money remained a mystery.
He said: “These bundles are always left in plain sight such as on pavements and discovered by random members of the public who have handed them in.
“This is the fourth bundle handed in this year. This could be the work of a Good Samaritan but we would like to thank the residents who have shown incredible community spirit by handing the money in.
"The circumstances remain a mystery so we would welcome any information that will help us get to the bottom of these random incidents."
If you have any information call 101 and ask to speak to DC Forster at Peterlee CID.
Police say the money is held for two weeks to give the owner a chance to come forward, before it is returned to the finder.
