HOUSTON (REUTERS) - A tanker carrying disputed Iraqi Kurdish crude oil reappeared on satellite tracking on Monday near Texas, days after having gone silent with a US$100 million (S$125.03 million) cargo, but the latest vessel data showed it had not offloaded at sea.

According to AIS ship tracking data used by the US Coast Guard and Reuters, the United Kalavrvta, which has been in limbo for weeks, was still 95 per cent full.

Its would-be US buyer has balked at taking delivery of the cargo, and Baghdad has filed a lawsuit in a US court saying exports by the Kurdistan Regional Government (KRG) are illegal. The KRG argues they are allowed under the Iraqi constitution.

The vessel was anchored on Monday in the Galveston Offshore Lightering Area, essentially unmoved from its previously known position.

Vessels such as the United Kalavrvta, which are too big to enter ports near Houston, use the lightering area to transfer their cargoes to smaller ships before delivery.

Baghdad has made clear it could file more legal challenges to regain control of the cargo if it comes ashore.

Several other tankers carrying crude from Iran or Iraqi Kurdistan have in the past unloaded cargoes after switching off their transponders, which makes their movements hard to track.

The partially full Kamari tanker carrying Kurdish crude disappeared from satellite tracking north of Egypt's Sinai about a week ago. It reappeared empty two days later near Israel.

And in July, the tanker United Emblem offloaded part of its cargo of Kurdish crude onto another ship in the South China Sea.

The US suit shows Baghdad is stepping up a legal and diplomatic push to stop Kurdistan from exporting crude, which the Kurds say is crucial to their dreams of independence from Iraq.