In affect, a Brit judge has blasted the child tax credit system which allows foreign mums to claim tax credits for their kids while living in Britain.
The masqueraded mum, Caockmari Omoike created 18 kids, and then rang the Inland Revenue.
Bungling benefits staff spoke to her on the phone 200 times. But they failed to smell a rat, and handed her 20,900 pounds in just four months.
After knowing of the incident, Judge Anthony Ensor said he was 'disturbed' by how easy it was to claim for nonexistent children and demanded tax chiefs tighten up procedures urgently.
Omoike, born in Gambia but now a Swedish national, took advantage of EU rules
She first invented nine kids living at her one-bed flat in Crumpsall, Manchester.
Then she gave herself a false identity and dreamed up nine more, with similar names to her first 'brood'.
Judge Ensor said he was worried by the simplicity of her con.
"It is disturbing that alarm bells did not ring when the seventh and eight child were claimed for within weeks of the previous child appearing," The Sun quoted Ensor, as saying.
"I would hope steps have been taken to ensure the authorities are more vigilant," he added.