Southwark Council has reported itself for a data breach, after the names and addresses of three residents on the Ledbury Estate were left on a document which was made public.

Speaking at an overview and scrutiny meeting, Councillor Maria Linforth-Hall asked the committee why the information appeared in the appendices of the agenda for the meeting, but was assured the document had been taken offline and the paper removed from the printed versions of the agenda.

In a statement, councillor and chairman of the scrutiny committee Bill Williams, said: “Part of one of the reports that came to the scrutiny committee this week included case studies taken from residents, and while personal details had been removed from the vast majority of the report it turns out that three names were accidentally left into the version that went public.”

He said the council “takes any breach of data protection very seriously and as soon as the matter was raised to officers, on the afternoon of the meeting, steps were taken such as removing the report from the council’s website and taking out the relevant page in the papers that had already been printed for that evening.

“It was also reported immediately to the council’s information governance team.”

But Ledbury Action Group co-founder Danielle Gregory, who read the documents before they were taken offline, alleges disputes between neighbours, health conditions, ongoing legal claims and private emails were also in the documents – which were part of auditors report on the council’s handling of issues at the Ledbury Estate.

“It was about 20 pages or so of different types of info,” she said.

“In the appendices the auditors had given examples of issues being raised, names and addresses, detailed ongoing legal claims and particulars of those claims, the basis they were claiming on.

“In some cases it reflected confidential disputes between neighbours, and health conditions, and copied sections of emails of complaints made to councillors,” she said.

Ms Gregory said it was “insulting” for residents to have their information and private discussions made public.

This comes as the group is seeking legal action against the council for having access to conversations between residents on a private Facebook group.

After applying to the council for a subject access request, Ms Gregory found  screenshots from a private Facebook group for residents had been shared between council officers.

“It was a residents’ only group, completely private, where residents can come together and discuss things,” she said.

But councillor Stephanie Cryan, cabinet member for housing management and modernisation, said the messages were not confidential.

“We can confirm that some emails sent to the council from a resident, which contained screenshots of messages posted by members of the Facebook group that they were part of, were passed on to other council officers for information. The emails were not confidential and were sent to the council to demonstrate concerns, which the council was asked, correctly, to respond to. We have written to the campaign group’s solicitors rejecting any claims to the contrary,” she said.