Thiruvananthapuram, Senior Congress leaders from Kerala on Friday urged Prime Minister Narendra Modi to order a NIA-CBI-RAW probe into the gold smuggling case in the state.

The party has already demanded that Chief Minister Pinarayi Vijayan should resign.

Addressing a press conference, state Congress unit president Mullapally Ramachandran, Leader of Opposition Ramesh Chennithala, and former Chief Minister Oommen Chandy said that all of them have signed the letter sent to Modi in this regard.

The decision was taken soon after the political affairs committee of the state Congress met.

Ramachandran said this is "rarest of the rare case". "Even though we welcome the NIA probe announced by the Centre since there is alleged involvement of Vijayan's office. His Principal Secretary M. Sivasankar has only been asked to go on leave and not even suspended, as he is the closest aide of Vijayan."

"Another reason is that the present state police chief has worked in the National Investigation Agency in the past... one week has elapsed since the gold smuggling case came to light and the prime accused woman is still on the run. She is understood to have links with all (ruling party) bigwigs," said Ramachandran.

Chennithala pointed said that the NIA could look into only certain aspects of the probe, while the CBI has expertise in all sectors, including economic offenses. Research and Analysis Wing has to be there because this involves India and the UAE.

"Hence, a joint probe is a must. We are surprised that Vijayan is now running away from questions. His office has to be included in the probe... Sivasankar is Vijayan's agent and hence he is being protected. It's unfortunate that the lady (Swapna Suresh) is on the run while the Kerala Police is silent and not even trying to trace her. So all know how things are," said the Congress leader.

Chandy denied any role in giving Swapna a job in the government and said that Vijayan should seek a CBI probe.

"I am being targeted. One report says I gave a job to the lady; but I had no role. Then came another picture of mine standing with arrested accused Sarith (former PRO of UAE Consulate). When I saw the picture, I realised it was morphed... it was taken last week at the house of a Congress worker who got married recently. The probe should go in the right direction and for that the NIA, CBI and the RAW have to be there," said Chandy.

Customes officials had seized 30 kg gold from a diplomatic consignment at the Trivandrum International Airport on Sunday, in which prime suspect Swapna was said to be involved. She is said to be close to ruling Left Democratic Front government in the state.