Tulisa Contostavlos said her life had been "ruined" for the last year by what she called "entrapment" from an undercover reporter working for the Sun.
Speaking outside Southwark Crown Court, the singer and former X Factor judge called on the police and the Sun's publishers, News UK, to look into Mazher Mahmood's conduct.
The judge in the case said there were "strong grounds" to believe Mahmood had "lied" and given "entirely inconsistent" evidence.
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The slump will spark scrutiny, especially as statistics show a rise in racially or religiously motivated offences following the EU vote.
The 53-year-old was killed shortly after leaving her home in Mosta, Prime Minister Joseph Muscat said.
Jordi Sanchez of the Catalan National Assembly and Jordi Cuixart of the Omnium Cultural group were jailed on Monday.