The Central Bureau of Investigation on Monday served summons on Kadapa MP Y S Jaganmohan Reddy issued by a court last week seeking his appearance in an alleged illegal assets case.

A team of CBI officials personally served the summons to YSR Congress leader Jagan in Yemmiganur town of Kurnool district, where he was campaigning for the next month's by-elections for his party candidate.

Jagan, son of late Chief Minister Y S Rajasekhara Reddy, has been directed to appear in person or through his lawyer before the principal special judge for CBI cases in Hyderabad on May 28.

Summons were also issued to 12 others who are facing charges in the case, including managing directors -- Srinivasa Reddy (Hetero Drugs), Nityananda Reddy (Aurobindo Pharma), Sarat Chandra Reddy (Trident life Sciences), senior Indian Administrative Service officer B P Acharya, AP Industrial Infrastructure Corporation's former officer Y Vijayalakshmi and former company secretary of Aurobindo Pharma, Chandramouli.

Acharya is already in judicial custody in the Emaar-APIIC township case, while Jagan's auditor Vijayasai Reddy, who was released on bail on April 30, was not issued summon as he has been attending the court proceedings regularly.