Three officials from the US Consulate General at Chennai on Monday visited the central prison at Palayamkottai where 35 crew members of a US firm owned ship, arrested for allegedly carrying arms in Indian waters, have been lodged.
Prison sources said the officials enquired about the health and other details of the crew.
The officials also enquired about Chief Engineer Sedo, a Korean, who allegedly attempted suicide by hanging himself from the flagmast on October 19, they said.
Asked about the visit, a spokesperson from the US Consulate General said, "We do not have any comment at this time, but are monitoring the situation."
She also maintained that there was no US citizen on the vessel.
Meanwhile, Tamil Nadu Police said a local agent of AdvanFort, which owns the ship, procured some 1,500 litres of high speed diesel from Tuticorin and transported it by a fishing boat on October 11.
'Q' branch of the police, dealing with extremist activities, had on Sunday arrested five local fishermen on charges of illegally supplying diesel, and a court remanded them to judicial custody.
Police had arrested all 35 crew members of MV Seaman Guard Ohio, impounded since Oct 12 for entering Indian territorial waters carrying arms and ammunition, without authorisation.
The ship reportedly had 35 assault rifles and around 5,680 rounds of ammunition, which were seized by police.
An FIR was filed against 10 crew and 25 security guards of the vessel on October 14. Among the crew, eight are Indians and two Ukranians.
The ship was intercepted by the Coast Guard at 10.48 nautical miles from the Indian shore within the territorial waters on October 12 and an FIR was registered against 35 persons onboard under the Arms Act and Essential Commodities Act for buying 1,500 litres of diesel illegally with the help of a local shipping agent.