An ExxonMobil rig that ignited a maritime boundary dispute between Guyana and Venezuela has now left the area, a Guyanese official said Monday, denying it was because of Venezuelan pressure.

Guyana's Natural Resources Minister Raphael Trotman said the Deepwater Champion left the disputed area because its exploratory work was done, having found a major deposit of high quality crude oil.

"Once the discovery was made, there is no more need for an exploration rig. You now have to have a production platform," he told AFP.

He said ExxonMobil is continuing to conduct seismic studies to "see if there are other wells nearby."

Venezuelan suggestions that ExxonMobil moved the rig because of pressure was nothing more than posturing ahead of elections, he said.

"They are on their hustings over there and we continue to conduct our business over here as per normal," he said.

In March, ExxonMobil set off a round of recriminations between Venezuela and Guyana after making a significant oil find in an offshore concession granted by Georgetown.

Venezuela, which has long had claims on Guyana's Essequibo region, charged that the concession was in disputed waters.

President Nicolas Maduro issued decrees extending Venezuela maritime boundaries to include the seas off the Essequibo region, which makes up two thirds of the territory of the former British colony, and declaring those waters as part of its integrated defense zone.

Last week, Maduro met with UN Secretary General Ban Ki-moon seeking UN support for mediation, while Guyana's President David Granger called for a definitive legal settlement of the dispute in the Hague.

Ban has decided to send a fact-finding mission to Caracas and Georgetown.

Guyana maintains that valid land borders were set in 1899 by an arbitration court decision, a decision Venezuela has never recognized.

Guyana claims a long-standing UN-led mediation process meant to resolve the dispute has yielded little results and that its neighbor is using the delays to its advantage.