The Mumbai based journalist has been accused of giving out the details of the bike number of Jyotirmoy Dey and his residence to Chotta Rajan, whom she thought was a party with the Chotta Shakeel gang.
The name of the accused is said to be Jigna Vohra, a journalist from a leading English Daily-Asian Age.
"Jigna Vora, deputy bureau chief of English daily Asian Age, has been arrested today as she played a role in the conspiracy hatched to murder J Dey," Joint Police Commissioner (Crime) Himanshu Roy.
The journalist will be produced in a sessions court today, said reports.
Crime Journalist Jyotirmoy Dey was murdered in broad daylight by unidentified assailants, who were later found out to be hired by Chotta Rajan.