Twice But Nice staff are asking once again not to leave donations at the store when the store isn't open.

A large number of items were left outside over the Christmas holiday, only to turn into a pile of junk by the time staff returned to work and find them.

Items left outside are bound to be looted through, damaged and ruined by thieves and weather, staff noted this week.

"Clothing left in the snow become wet and moldy," the store posted. "When items are dumped over the closure period, your donations are susceptible to being damaged. This take away our resources within the store, spending hours cleaning broken glass and soiled items in our back area to make it safe for our staff, volunteers and those who donate.

"We would like to reiterate how thankful we are for all your donations — but we discourage dumping on non-donation days."