The Department of Health has apologised for misleading MPs by giving incorrect figures on tattoos removed on the NHS.
The NHS says it is not possible to say how many tattoos are removed
Health minister Rosie Winterton said in October that 187,063 tattoos had been removed last year. Some experts later estimated this could have cost £300m.
But the department now says the figure was a mistaken estimate and that the true amount was not known.
The error was uncovered during a debate in the Lords and condemned by Tory Lord Tebbit as "extraordinary".
In a written ministerial statement, the Department of Health apologised for the error and said steps had been taken to ensure it did not happen again.
It said the figure was provided by the NHS Information Centre, which had formally apologised and accepted full responsibility for providing an incorrect response.
The statement said: "The attempt was intended to be helpful, but ended up being misleading because it is not possible from the existing data sets to say with any precision how many tattoos are removed by the NHS each year."
It added that "clinical advice is that it is likely to be a far smaller number than the figure given".
Tattoo removal on the NHS is sometimes allowed for psychological reasons - criticised by some MPs and doctors who say money is being spent on trivial surgery while staff are laid off and patients denied potentially life-saving drugs.
Ms Winterton's original answer given on 18 October prompted the Sunday Times to report: "NHS blows millions on removing tattoos".
Its estimates put the cost of removing 187,063 tattoos under anaesthetic at at least £37m, but some consultants said it could run to £300m.
But Lord Tebbit said it was extraordinary the wrong figure had been given in the Commons, and had only been corrected once it was queried in the Lords.
"How can we give any credence to any answer about costs and statistics in the National Health Service when such things are allowed to go on unchecked until there is a further question in this House?" he said.
Last month Liberal Democrat MP John Hemming went to the High Court to request a judicial review into the quality of ministerial answers - and to ask whether they could be enforced through the courts. His bid was rejected.