The undercover reporter known as the "Fake Sheikh" has been charged by UK authorities with conspiring to pervert the course of justice after the collapse of the drugs trial of pop star Tulisa Contostavlos.
Mazher Mahmood, a former reporter on the News of the World, is alleged to have misled the court, the Crown Prosecution Service said.
In a statement issued through his lawyers, Mahmood said: "I am deeply disappointed that, after a totally unjustified delay, the Crown Prosecution Service have today informed me that they have decided to charge me with conspiracy to pervert the course of justice.
"I deny the offence. I will vigorously contest it at court.
"In the meantime I have nothing further to say."
Mahmood is charged alongside Alan Smith, a driver. The pair will appear at Westminster Magistrates' Court in London tomorrow.
Nick Vamos, deputy head of Special Crime at the CPS, said: "The CPS has today, Tuesday September 29, charged Mazher Mahmood and Alan Smith with conspiring to pervert the course of justice after a full file of evidence was submitted by the Metropolitan Police on 5 June this year.
"After carefully considering all of the evidence, the CPS has decided that there is sufficient evidence for a realistic prospect of conviction and it is in the public interest to charge both men.
"This decision comes after it was alleged that Mr Smith agreed with Mr Mahmood to change his statement to police as part of a trial in July 2014, and that Mr Mahmood then misled the court."