Kochi, July 29 : The NIA on Tuesday questioned suspended IAS officer M. Sivasankar in the Kerala gold smuggling case here for over 10 hours before allowing him to return to his home in the state capital. This is the third time in the past five days that he has been interrogated. On Monday, after being questioning by the NIA for nine hours, Sivasankar was served a notice to appear before them on Tuesday again. On Tuesday, he arrived at the NIA office here around 10 a.m. and was allowed to go back at 8.30 p.m. The questioning was led by a woman IPS officer of the NIA from Hyderabad, while other officers were linked online from various offices in the country. The NIA had questioned Sivasankar in Thiruvananthapuram for five hours on July 23 and served him notice to appear at its Kochi office for further questioning on Monday. After Monday's exercise, he stayed the night at a hotel near the NIA office. Sivasankar is a former Principal Secretary to Chief Minister Pinarayi Vijayan and Information Technology Secretary before he was removed from the post after the racket came to light. In the state capital, when media persons asked the Chief Minister about the questioning of his former top aide and the frequent demands of the Leader of Opposition Ramesh Chennithala for his resignation, a peeved Vijayan shot back: "He (Chennithala) has a special frame of mind and naturally, he will speak like this only." He also reiterated that the ongoing questioning of his former secretary will, in no way, affect his government. Leading lawyer S. Rajeev, from whom Sivasankar had sought legal advice, told the media that the investigation of a very important case of national interest has only begun. "The NIA will now continue to collect evidence in the case and any investigation agency can call up anyone any number of times for taking statements," said Rajeev, soon after Sivasankar left the NIA office to return to his home in the state capital. This case has rocked Kerala all this month and has caused a huge dent to the image of Vijayan, who continues to maintain that this was a private affair concerning Sivasankar and his office has nothing to do with it. But, the social media is buzz with the position he took against his predecessor Oommen Chandy, when con woman Saritha Nair was arrested for cheating investors in the solar panel case. Vijayan is being reminded of his speeches on the need for a Chief Minister to maintain a clean image in public life during Chandy's time. His then rhetoric that Chandy "has no moral right to continue in the post", is making the rounds on social media. The gold smuggling case first surfaced when P.S. Sarith, a former employee of the UAE Consulate here, was arrested by the Customs on July 5 when he was allegedly was facilitating the smuggling of 30 kg gold in a diplomatic baggage from Dubai to Thiruvananthapuram. The case became murkier when the name of Swapna Suresh, a former employee of the UAE Consulate and later employed with the IT Department, came to light. Her links with Sivasankar came up later during the investigation. Another accused, Sandip Nair of Kochi, was arrested on charge of direct involvement in the smuggling. The Customs had first quizzed Sivasankar for nine hours, after the case surfaced and they arrested Sarith. Swapna and Sandip were arrested by the NIA from Bengaluru. Sivasankar has maintained all through that his relations with Swapna were personal and not linked to his work. /IANS