PLANKS of wood, smashed windows, sinks and other building waste, thought to have been collected from homes around London, were dumped in fields between Riddlesdown and Warlingham.
Travellers thought to have broken the lock on the gate next to Tithepit Shaw Lane have been blamed for the mounds of rubbish left in Dipsey Field last week, one of the largest fly-tips the area has suffered.
Nearby residents said about eight caravans pitched up in the field, well used by runners and dog walkers, on Monday night and left under orders from Croydon Council on Friday morning.
Smaller amounts of household rubbish were left throughout the week, they added, with the huge piles of building waste appearing on Thursday afternoon.
Mail and packages among the building waste were labelled with addresses in areas including north London, Penge, and as far afield as Birmingham.
Frankie Wheeler, who walks her dog in the park, said: "It seems they are collecting the building waste and just dumping it here.
"They have been nearby before and always leave rubbish, but never before this deliberate collecting and dumping."
She added: "It was horrendous. Absolutely horrendous. There will be broken glass around for months.
"It does not matter how carefully you pick it up, you are not going to get all of it."
Nicki Clark, who organises the weekly Riddlesdown Parkrun, was among nearby residents who spent hours clearing up piles of rubbish ahead of Croydon Council taking away heavier items.
She said: "It was horrible. There were seven of us up there for three hours.
"Most of the stuff [we cleared] was dumped from their caravans, food waste.
"There were dirty nappies, bags full of human excrement, all the sorts of things you would put in your kitchen bin, and there was evidence of drug use as well.
"You would not want to go near it – it stank."
The lock on the gate has since been changed.
A spokesman for Croydon Council said there was no estimate yet as to how much it would cost to remove and dispose of the rubbish.
"As with all fly-tips, the content will be searched for clues as to the identity of whoever is responsible," the spokesman added.
"Entrance to the land, formerly part of Warlingham Court Farm, has been temporarily blocked pending the installation of a permanent gate offering more security than that which had been in place previously."
