The Supreme Court has cautioned judges against treating anonymous letters as PILs and asked them to be vigilant against unscrupulous elements who abuse the judicial process for vested interest through such petitions.

"In our view, the public interest litigant must disclose his identity so as to enable the court to decide that the informant is not a wayfarer or officious intervener without any interest or concern," a bench of Justices S H Kapadia and B Sudershan Reddy said.

In their 58-page judgement, the judges said High Court judges cannot entertain letters or petitions addressed to them directly as it is the prerogative of the Chief Justice (of a High Court) to mark the matter to a particular bench.

The bench made the observations while taking exception to the Kerala High Court's move to treat an anonymous letter as a PIL.

The High Court ordered a probe by a Special Investigation Team (SIT) into alleged incidents of sexual exploitation and murders at a religious centre in Thrissur district.

Holding that the High Court exceeded its jurisdiction, the apex court quashed the probe against "Divine Retreat Centre" by the SIT and restored the investigation to the local Circle Inspector at Koratty Police Station, Thrissur district.

The anonymous letter allegedly pointed an accusing finger towards some Christian priests and IAS and IPS officers allegedly associated with the Centre.

The anonymous letter addressed to Justice Padmanabhan Nair alleged about sexual exploitation of women and murders in the "Divine Retreat Centre."

It accused the local police of harassing the victims instead of taking action against the accused.