Iain Duncan Smith has been accused of misleading the public after welfare officials were forced to delete a series of made up quotes from a benefits leaflet.
Mr Duncan Smith faced sharp criticism after the Department for Work and Pensions he heads up was forced by the Welfare Weekly publication to concede "Sarah" and "Zac" did not exist and the images on the leaflet were stock photographs.
The DWP insisted the case studies were "based on conversations our staff have had with claimants" and were dreamed up "to help people understand how the benefit system works".
In the leaflet, "Sarah" was quoted as expressing delight at having been persuaded to draw up a CV under threat of having her payments docked.
"My benefit is back to normal now and I'm really pleased with how my CV looks. It's going to help me when I'm ready to go back to work," the quote said.
"Zac" was more conscientious, telling readers he had not missed out on any benefits because "I had a good reason for not going to the meeting and proof of the appointment".
Labour accused the Work and Pensions Secretary of trying to cover up failures in the benefits sanction regime.
Acting shadow work and pensions secretary Stephen Timms said: "You couldn't make it up - but it seems Iain Duncan Smith can. The only way he can find backers for his sanctions regime is by inventing them.
"Instead of fabricating quotes pretending the system is working, he should scrap unfair sanctions targets for Jobcentre staff and do more to protect vulnerable people from facing benefit sanctions."
Leadership candidate Andy Burnham said: "The DWP has been caught red-handed. Iain Duncan Smith must come clean on any knowledge of these fakes.
"It is further evidence of a shambolic Tory benefits policy. David Cameron is hell-bent on hurting the most vulnerable ... and under my leadership, Labour will oppose his Welfare Bill."
Initially the DWP did not rule out continuing to "test" the original version with the fictional characters alongside one where the pictures were silhouetted and a note was added that they were "illustrative".
However a spokeswoman said that approach had been abandoned.
One of the invented quotes - and another different one - also appears next to stock photos in a separate sanctions leaflet accessible on the DWP website - though this time without a fictional name attached.
One of the pictures is the same as the one used to illustrate "Zac" - but in this instance he is talking about being sanctioned, rather than having a good reason to miss his appointment.
The words attributed to his character in the recent publication are displayed alongside a photograph of a different man.
Learning disability charity Mencap accused the Department of "unacceptable" behaviour.
Head of policy Dan Scorer said: "DWP's made-up case studies present an unrepresentative view of the sanctions regime and its impact on disabled people.
"Benefits are a lifeline to many people with a learning disability who rely on them to make ends meet.
"We know many people have been sanctioned because Jobcentre staff don't understand their needs and place unrealistic demands on them while not providing support they need.
"To mislead the public on the effects of benefit sanctions in this way is unacceptable."
The Unite union's assistant general secretary Steve Turner said: "This is a shameful attempt by Iain Duncan Smith to bend the truth and gloss over the human misery of his cruel sanctions regime.
"In the last two years over two million people have been sanctioned, often for just arriving minutes late to a meeting or in some circumstances for attending a family funeral.
"This has left people destitute and unable to heat their homes or feed their kids.
"Iain Duncan Smith should be scrapping his heartless sanctions regime rather than trying to defend them through made up quotes and fictional characters."