The vessel has been held unlawfully, Pinarayi Vijayan said.
As the families of 16 Indian sailors including three from Kerala, detained in Equatorial Guinea, hoped the Indian government will ensure their speedy release, Kerala Chief Minister Pinarayi Vijayan on Tuesday requested Prime Minister Narendra Modi to intervene in the matter.
In a letter to the Prime Minister, Pinarayi Vijayan requested him to direct Indian diplomatic missions in the countries concerned -- Equatorial Guinea and Nigeria -- "to proactively intervene and facilitate the immediate release of the Norwegian vessel -- MT Heroic Idun -- and its crew who have been detained since August 12".
In his letter, the Chief Minister contended that the vessel was arrested by an Equatorial Guinea naval ship in international waters on August 12 and as per reports, a total of 26 crew, including 16 Indians, are being held as hostages.
"Among the 16 seafarers, three are from Kerala. The vessel has been held unlawfully," he added.
Mr Vijayan also claimed that even though the vessel did not engage in any unlawful activities, the shipping company was ready to pay the fine to facilitate the early release of the seafarers.
"After negotiation with the Nigerian authorities, the shipping company paid the required fine on September 28. Unfortunately, the crew and ship are still held in Equatorial Guinea under arrest till date," he said in his letter.
He further said that the "unforeseen delay" in the sailors' release would affect the mental and physical health of the crew and further stay in the port, which is considered unsafe, "would also put their lives in danger."
"I request your good self to direct the diplomatic missions in the countries concerned to proactively intervene and facilitate the immediate release of the vessel and its crew members," Mr Vijayan said in his letter.
The communication comes in the wake of videos and photos sent by the detained Kerala sailors to their families widely circulating on social media as well as news channels.
One of the videos is by Vijith Nair, the brother of Vismaya who died by suicide in June last year due to dowry harassment -- an incident which led to widespread debate in the state regarding this practice.
Vijith, in the video, has said that 15 crew members, including him, have been locked in a jail at Malabo, the capital of Equatorial Guinea, surrounded by security personnel after they were taken from their vessel on the pretext of being accommodated in a hotel.
The visuals show the sailors lying on the floor in one room and Vijith saying that soon his phone would run out of battery and that the mobile might even be confiscated.
He is seen requesting everyone to share the video so that it reaches the authorities concerned.
Earlier in the day, another sailor from Kerala-- Chief Officer Sanu Jose -- spoke to a TV channel via video call during which he said that he was taken to an Equatorial Guinea warship, but then the Equatorial Guinean government decided not to hand over the Norwegian vessel and crew to Nigeria and he was taken back to his ship.
He also said that 15 crew members, including Vijith and another sailor from Kerala- Milton, were not in the ship when he returned and he was informed that they have been taken to the shore.
Jose also said that arrest and detention of the vessel and crew was all done unofficially and there were no official records of the same.
Everything was being done at gunpoint and by intimidating us, he claimed and at the same time also said that no one was physically abused by their captors.
"I want to return home. I want to see my kids. I have two small kids," he said during the video call.
His wife told a TV channel that it was a relief that the sailors were not handed over to Nigeria and she hoped the Indian government would intervene to ensure their speedy release.
She said that she has not received any information or communication from the Indian government.
She as well as the wife of Milton, however, were concerned that 15 sailors were locked up in a room in the capital city of Equatorial Guinea.
The Indian Embassy in that country said on Monday that it has been in regular contact with the crew members over phone.
"This Embassy and our High Commission in Abuja are closely working with authorities of Equatorial Guinea and Nigeria for the early release of crew members of MV Heroic Idun. All crew members are safe and those in the Detention Centre have been shifted to the ship," the Indian embassy in Equatorial Guinea had tweeted.
"Since their detention in mid-August, this Mission has been in regular contact with the crew members over phone. We have also had several consular access/ visits to them. We are closely monitoring developments and are actively engaged for an early resolution of the issue," it had added.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)