Thiruvananthapuram, Nov 5 : The Enforcement Directorate has served a notice to the assistant private secretary of Chief Minister Pinarayi Vijayan. C.M.Ravindran is to appear before the ED at their Kochi office on Friday. The notice was served as gold smuggling case prime accused Swapna Suresh's relation with Ravindran surfaced. Soon after Vijayan's secretary and senior IAS official M.Sivasankar was arrested last month by the ED after his anticipatory bail plea was rejected by the Kerala High Court, reports had surfaced that next person on the ED radar would be Ravindran. Ever since the gold smuggling nexus came to light, Vijayan has said that as the probe intensifies, heartbeats of many will increase. However, after the arrest of Sivasankar and the subsequent arrest of CPI-M state secretary Kodiyeri Balakrishnan's son Bineesh Kodiyeri, the opposition leaders from the Congress and BJP have taken potshots at Vijayan, asking the rhetorical question: "Whose heartbeat?" Ravindran has been in the personal staff of Balakrishnan in 2006-11, when he was the Home Minister in V.S. Achuthanandan and later when Achuthanandan became the Leader of Opposition (2011-16) again he was present and when Vijayan took over as Chief Minister in 2016, Ravindran willed major power. Political analysts feel what brews trouble is that the probe agencies might have established a Sivasankar-Ravindran axis in the office of Vijayan -- that was the deciding factor and was the last word, when it came to decision making. Soon after Sivasankar's arrest, the CPI-M leadership tried to play it like -- Sivasankar being an IAS officer -- a central government employee, so more than Vijayan, it was Prime Minister Narendra Modi, who should be worried. Should things turn sour for Ravindran, Vijayan could also feel the heat. /IANS