A Brent Council spokesperson said:
"As soon as we became aware of this mistake, it was immediately flagged with the council's Information Governance team who are working with the team concerned.
"We have already apologised to the recipients and made them aware it was not intentional and due to human error. We're also exploring ways of ensuring that this type of error cannot happen again in consultation exercises.
"We would encourage people to participate in the Neasden consultation and offer us their ideas on making the area around Neasden Station a nicer and better place for people in Brent. "