A tanker loaded illegally with crude from a rebel-held port and intercepted by the US Navy arrived Sunday off Tripoli and its crew were detained, Libyan maritime and official sources said.
The official news agency Lana said the 21 crew members of different nationalities and three Libyans on the tanker "Morning Glory" were handed over to judicial police.
The ship's captain and the three Libyans were being questioned, said the prosecutor general's spokesman Al-Seddik al-Sour.
After its arrival off the capital early on Sunday, the tanker headed off towards Zawiya port, 50 kilometres (30 miles) to the west, a Libyan maritime source said.
The US Navy handed over the Egyptian-owned tanker on Saturday to its Libyan counterparts.
"We have been assured by the government of Libya that the captain, crew members and Libyan nationals who were aboard the stateless tanker will be treated humanely in accordance with internationally recognised standards of human rights," the US embassy in Tripoli said.
US Navy SEALS captured the Morning Glory off Cyprus in the eastern Mediterranean last Monday.
The ship the previous week evaded the Libyan naval off the eastern port of Al-Sidra -- controlled by rebels seeking autonomy from Tripoli -- after reportedly being loaded with some 234,000 barrels of crude.
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The weak Tripoli government's failure to stop the Morning Glory had plunged Libya into one of its biggest crises since Moamer Kadhafi was toppled by a NATO-backed uprising in 2011.
Its escape after Libyan authorities had repeatedly vowed to take all measures to stop it underscored the weakness of the central government, which has struggled to rein in heavily armed former rebels.
But on Sunday, the Libyan navy's chief of staff, Hassan Boushnak, told reporters that the US intervention had saved the tanker from being bombed.
"The intervention of US forces who feared an environmental catastrophe in the Mediterranean prevented us from destroying the ship," he said.
Rebels pressing for autonomy for Libya's eastern Cyrenaica region -- epicentre of the revolt against Kadhafi -- have been blockading oil terminals in eastern Libya since July.
That has led to a decline in exports from 1.5 million barrels a day to just 250,000.
The Morning Glory incident marked a major escalation and triggered the ouster of liberal-backed prime minister Ali Zeidan.
The tanker was originally a North Korean-flagged ship, but Pyongyang said it had "cancelled and deleted" its registry on the grounds it was carrying contraband material.