Names and addresses of witnesses could still be in the hands of known troublemakers, months after a catastrophic town hall data leak.

Islington Council has admitted that it has failed to retrieve at least one and possibly two of the bundles mistakenly handed to 10 suspected drug dealers on the Andover Estate in April.

The Gazette can also reveal that six of the eight households which were promised moves over safety fears are still waiting.

Cllr Greg Foxsmith, of the Lib Dem opposition, said: “As long as the documents are still out there, they can be copied and passed around. Even if they get them back, we will never know that the information isn’t out there – it’s an ongoing worry.”

“I’m advising one resident who is yet to move. She is very anxious and I’m concerned for her.”

Meanwhile, a report commissioned in the wake of the scandal has been published – and it warned of a repeat if procedures are not overhauled.

The council has refused to disclose another report into the specifics of the blunder, in which the names, street names and phone numbers of 51 people were disclosed in court orders banning the 10 youths from the Andover Estate, off Hornsey Road, Holloway.

But legal director Louise Round blamed the mistake on a rush to get the work done before the weekend.

She said one of the council’s lawyers forgot to blank out the confidential details as she hurried to secure the bans. The lawyer was disciplined but not dismissed.

Cllr Terry Stacy, leader of the Lib Dem opposition, said: “You couldn’t make it up. No responsibility. No change. No sackings. No housing transfers. Not all the legal papers back. Just more spin from Labour.”

The council has vowed to tighten up processes and said a new computer system would eventually make a repeat all but impossible. In the meantime, sensitive documents will be double-checked.

Cllr Paul Convery, executive member for community safety, said: “This was a pretty catastrophic blunder and it rang alarm bells. It has been a scarring experience for everybody, but we have amended our mistakes and done the right thing for people affected.

“Hopefully we have done everything we can to avoid something like this happening again.”

The incident will be discussed at a scrutiny meeting tonight (Thursday).