Additional Chief Metropolitan Magistrate Samar Vishal absolved the politician of the charge citing various anomalies in the charge sheet filed by Delhi Police.
Mr Singh was on August 5 last year taken into judicial custody for repeated non-appearance in the case. However, he was granted bail on furnishing a personal bond later in the day.
While discharging the AAP politician, the judge said, "I am of the view that the manner in which prosecution is launched as well as even on merits the accused deserves to be discharged."
The court noted that the complainant, a head constable, himself became the investigating officer, putting the concept of investigation at stake.
It also said that there was no investigation on whether the accused himself had put up the banners and the charge sheet was "conspicuously silent" on that aspect.
The case relates to defacement of public property in the Naraina area in west Delhi allegedly by putting up posters and hoardings.
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