Sloppy administration by senior council officers resulted in emails about a controversial railway development going missing, a judge has said.

Lambeth Council failed to produce correspondence relating to the works at Streatham Hill sidings following a Freedom of Information (FOI) request, a tribunal at the Royal Courts of Justice has heard.

Judge Fiona Henderson said there had been “inconsistent and poor administrative practice” by council officers after Streatham Hill councillor Jeremy Clyne submitted an appeal to the Information Commissioner, arguing key information had not been released.

She subsequently ordered deleted emails from a senior officer’s account should be restored and said files held by cabinet member Councillor Paul McGlone, who had several high level meetings with representatives from developer Southern Rail, must be produced.

In November 2010, residents lost their five-year battle with Southern to remove parts of a 300m cleaning and maintenance depot, which had been built without permission.

At the tribunal, planning officers conceded they had redrafted a report by an independent railway expert about the development.

Coun Clyne: “This judgment vindicates my decision to pursue the circumstances in which a key report was changed. But it’s regrettable I should have had to go to these extreme lengths.

“Rather than the co-op council, this case shows a better title for Lambeth might be the cover-up council.”

A council spokesman said the judgement did not single out Lambeth for deliberately withholding information but had implications for local all authorities that delete staff emails a year after they leave office.