The former governor of Nigeria's oil-rich Delta¹ State has been cleared of 170 charges of corruption³ - involving the laundering⁴ of millions of dollars.

尼日利亚富含石油的尼日尔州前州长拜托170项贪污指控，包括数百万美元的洗钱活动。

A UK court has frozen assets worth $35m it says belong to James Ibori

The federal court in Asaba said there was no clear evidence against James Ibori, governor from 1999 to 2007.

The Economic and Financial Crimes Commission (EFCC), which brought the prosecution⁵, described the judgement as hazy朦胧的，模糊的 and pledged to appeal against提出上诉 it.

Nigeria is frequently cited as one of the world's most corrupt² countries.

Correspondents say the government has had to defend itself recently amid growing anger that it is slowing down its anti-corruption drive.

'No stone unturned'

The BBC's Caroline Duffield, in Lagos, says Mr Ibori is one of the most wealthy and well-connected politicians in Nigeria.

She says he is a close personal friend of President Umaru Yar'Adua, and is notorious声名狼藉的 among Nigerians for becoming extremely wealthy during his time in power.

The EFCC say they have "an enormity暴行，残暴" of evidence against him and have promised to "leave no stone unturned" in their efforts to bring a prosecution.

"This kind of judgement, if not challenged, is capable of deepening the menace威胁，恐吓 of corruption in our country," the commission said in a statement.

The EFCC initially⁶ brought charges against Mr Ibori in early December 2007.

But the EFCC has been at the centre of a political storm in recent years - dogged跟踪，尾随 by allegations of political bias偏见.

Former EFCC head Nuhu Ribadu was removed from his post just two weeks after the charges were brought against Mr Ibori.

Mr Ribadu was seen as close to Mr Yar'Adua's predecessor⁸ Olusegun Obasanjo.

And last week the EFCC arrested senior critics of the government - who accused the commission of working to disrupt their plans to launch an opposition⁹ party for the next election.

Wide powers

Meanwhile, the UK authorities have also acted against Mr Ibori.

In 1997 a UK court froze assets allegedly belonging to him worth $35m (£21m). His annual salary was less than $25,000.

He had already left the UK when his assets资产，财产 were seized.

But several of his associates同伴，合伙人 and his wife, Theresa Ibori, are facing trial on related charges in the UK next year.

Mr Ibori is named on legal documents as a co-conspirator in the UK case, which deals with alleged¹⁰ fraud欺诈 from more than one Nigerian state's coffers.

But no charges have been laid against him.

Under Nigeria's federal system, state governors enjoy wide powers.

Those running oil-rich states have budgets larger than those of some African countries.

They enjoy immunity¹¹豁免权 from prosecution while in power, but several have faced corruption charges since leaving office after the last election in 2007.

Just one former governor has so far been convicted - Edo State's former chief Lucky Igbinedion, who was fined $25,000 for embezzling盗用，挪用 $21m.