The Information Commissioner's Office has said it intends to fine 11 charities for breaking data-protection rules, but has not identified the organisations.
In a statement published today, the ICO said the charities had been informed of its decision and had 28 days to make representations against the findings.
The ICO said it would consider representations from each of the charities before making its final decision about enforcement action.
The regulator said it would name the organisations only if it decided to fine them after completing its investigations.
The notice said the charities had been investigated as part of a wider operation sparked by media reports "about repeated and significant pressure on supporters to contribute".
No other charities were still being investigated as part of that operation, the ICO said.
In July 2015, the ICO launched Operation Cinnabar, investigating the Daily Mail’s claims that charities were involved in the exploitation of loopholes in the Telephone Preference Service. And in September 2015 it launched Operation Linden after the same newspaper claimed that data-sharing among charities led to a man with dementia being tricked out of £35,000 by unscrupulous companies.
The charities that were originally the focus of Operation Cinnabar included Macmillan Cancer Support, the NSPCC, Oxfam, the Red Cross and Age International, but the inquiries into the Red Cross and Age International concluded last year after the charities signed agreements that committed them to renewing their telephone fundraising consents every two years.
The RSPCA and Age International said this afternoon they were not among the charities mentioned in the notice.
The NSPCC declined to comment on whether it had been informed that it was among the charities to be fined, and the other charities have yet to respond to Third Sector’s request for comment.
Peter Lewis, chief executive of the Institute of Fundraising, said: "A cloud has been hanging over the sector for too long about these investigations, so it is welcome that the ICO has today drawn a line under the speculation about the number of charities affected."
In December, the ICO levied fines totalling £43,000 against the RSPCA and the British Heart Foundation after ruling that both charities broke data-protection rules through participating in a data-sharing scheme.
Both charities initially disputed the findings but earlier this month said they would not appeal against the fines.