The Madras High Court yesterday issued notice to all respondents in the alleged illegal telephone exchange case on a petition by CBI challenging the order of discharge of former Union Minister Dayanidhi Maran and others.

When the petition by CBI came up, Justice G Jaichandran directed issuance of notice to all those involved in the case, returnable by June 20. A special CBI court had in March last discharged Dayanidhi Maran, his brother Kalanithi and others accused in the case.