Home Secretary Theresa May has been criticised for claiming that an illegal immigrant avoided deportation because of his pet cat.
She told the Conservative conference the ruling illustrated the problem with human rights laws, but England's top judges said she had got it wrong.
Her Cabinet colleague Ken Clarke said he had been "surprised" by the claim and could not believe it was true.
And human rights campaigners said Mrs May should get "her facts straight".
'Needs to go'
Mrs May made the remark during a speech in which she repeated her belief that the Human Rights Act, which incorporates the European Convention on Human Rights into UK law, "needs to go".
She also outlined how she planned to rewrite immigration rules to prevent "misinterpretation" of Article 8 of the convention - the right to family life.
She said the meaning of Article 8 had been "perverted" and used to prevent the removal of foreign national prisoners and illegal immigrants - more than 100 of whom successfully used it last year to avoid deportation.
She pledged to clear up any "misconception" by judges about what it meant.
"We all know the stories about the Human Rights Act... about the illegal immigrant who cannot be deported because, and I am not making this up, he had a pet cat."
But a spokesman for the Judicial Office at the Royal Courts of Justice, which issues statements on behalf of senior judges, said the pet had "had nothing to do with" the judgement allowing the man to stay.
Mrs May told the BBC her speech had been checked before it went out and that the case was "just one example" of where she believed the law was being misconstrued.
Human Rights Act
But she promised she would have "another look at the case", if it was proved to be wrong.
Asked about the reference, her Conservative cabinet colleague, Justice Secretary Ken Clarke, told the BBC: "The cat surprised me. I cannot believe anyone was refused deportation just because they owned a cat."
Later he told a fringe meeting that the case "certainly has nothing to do with the Human Rights Act and nothing to do with the European Convention on Human Rights".
And he said repealing the UK Human Rights Act would mean "all the cases go back to Strasbourg", adding: "I think it is a good idea that we remain adhering to the Convention on Human Rights and the cases are heard here by British judges."
Mr Clarke said he had not discussed with Mrs May her plan to change immigration rules to reduce the number of foreign criminals successfully using Article 8 to avoid deportation.
But he said it was "fine" to "remind people" about the scope of Article 8 as he believed there had to be an "extremely compelling" reason for convicted foreign criminals to remain in the UK.
For Labour, shadow policing minister Vernon Coaker said the government was not enforcing the rules that already existed.
"We have the ludicrous spectacle of the home secretary blaming cats whilst letting into the country a sheikh the home secretary thought she had banned and ending up paying him compensation as a result."
And Amnesty International said Mrs May's comments only fuelled "myths and misconceptions" about the Human Rights Act.
"That someone in Theresa May's position can be so misinformed as to parade out a story about someone being allowed to stay in Britain because of a cat is nothing short of alarming," the campaign group said.
"She urgently needs to get her facts straight."
The BBC News Channel's chief political correspondent Norman Smith said what had been intended as a major policy announcement had turned into a public relations shambles with Mrs May "overreaching herself" and Mr Clarke appearing out of the loop.
The case at the centre of the row occurred in 2008 and involved a Bolivian student who said he could show he had a proper permanent relationship with his partner and should not be deported.
The Bolivian man eventually won his case on appeal because the Home Office had ignored its own immigration rules on unmarried couples.