(Adds Shell declining comment, paragraph 4)
ABUJA, Dec 13 (Reuters) - Nigeria's lower house opened aninvestigation on Tuesday into an offshore oil field owned byRoyal Dutch Shell and Eni, the latest inquiryinto their acquisition of the OPL 245 licence block which couldhold up to 9.23 billion barrels of oil, according to industryfigures.
Earlier this year the Dutch and Italian authorities launchedtheir own investigations.
The acquisition in 2011 was a "breach of due process thatresulted in monumental revenue loss to the country," said YakubuDogara, speaker of Nigeria's House of Representatives.
A spokesman for Shell said: "As this matter is the subjectof current investigations, it would be inappropriate for us tocomment."
The licence was initially awarded in 1998 by former Nigerianoil minister Dan Etete to Malabu Oil and Gas, a company in whichhe was a shareholder.
It was then sold for $1.3 billion in 2011 to Eni and Shell.According to documents from a British court, Malabu received$1.09 billion from the sale, while the rest went to the Nigeriangovernment.
In 2014 a Milan court placed Eni under investigation overthe purchase and the probe was later widened to Shell. (Reporting by Camillus Eboh; Writing by Paul Carsten; Editingby Greg Mahlich/Ruth Pitchford)