Schools and a community centre have been targeted by lead thieves striking at night.
Since Thursday, August 28, there have been several lead thefts and attempted thefts in Shinewater, Langney, near Eastbourne.
In some cases, the valuable metal has been stripped from buildings and found ready for removal, suggesting the thieves may have been disturbed.
Acting Sergeant Jon Attfield, of the Langney Neighbourhood Policing Team, said: "Thanks to the vigilance of one local resident a quantity of lead has been recovered.
"This is being examined forensically and will help with our investigation.
"These thefts not only have a financial impact on our schools and community services, but can also affect children's education, closing facilities while repairs are carried out."
Anyone who may have seen anything suspicious or who has other information is asked to email firstname.lastname@example.org or phone 101, quoting serial 731 of 1/9.
Alternatively they can call the independent charity Crimestoppers free and anonymously on 0800 555 111.