By Senan Murray
BBC News, Abuja
Four former Nigerian governors accused of corruption are on the run from the anti-graft agency, after their terms of office expired on Tuesday.
Is this Dariye's final goodbye?
Elected officials enjoy immunity from prosecution while in power.
The runaway governors did not hand over power in inauguration ceremonies held across the country.
Anti-corruption officials say they want to investigate most of the 36 outgoing governors but critics say the probes are political.
Under Nigeria's federal system, governors enjoy wide-ranging powers. Some control annual budgets of more than $1bn in Africa's largest oil producer.
Plateau State's Joshua Dariye, who skipped UK bail three years ago after he was arrested for money-laundering, failed to turn up for the swearing-in ceremony in Jos.
Insiders say he is running away from the Economic and Financial Crimes Commission (EFCC), which has been trying to arrest him since he jumped bail in the UK.
Local state legislators impeached him last November after they found him guilty of corruption.
Before the EFCC could get to him, however, Mr Dariye gave them the slip but returned to power three weeks ago after the Supreme Court ruled that his impeachment was not constitutional.
Other former governors running away from prosecution are former Vice-President Atiku Abubakar's self-proclaimed "political godson" Boni Haruna of Adamawa State.
Mr Haruna packed out of government house in the north-eastern town of Yola on Sunday for an undisclosed location.
But his spokesman Abdulrazak Namdas says Mr Haruna was "resting" in Nigeria's largest city, Lagos.
The EFCC is investigating Mr Haruna for allegedly embezzling state funds.
His "godfather", or political backer, Mr Abubakar, who has also been accused of corruption, flew out of Nigeria shortly after he lost out in a presidential election won by the governing party's Umaru Yar'Adua.
The former vice-president's spokesman says Mr Abubakar is presently recuperating from major surgery and his absence at Tuesday's handover of power was mainly due to his belief that the elections were not free, fair or credible.
"He said he did not wish to confer legitimacy on the charade by his presence at the handover," Garba Shehu told the BBC News website.
Another ex-governor, Chimaroke Nnamani, was not in Enugu to hand over to his successor either.
Mr Nnamani, who has had a run-in with the EFCC, is said to have fled to Spain to escape arrest.
Former Jigawa State Governor Saminu Turaki is also believed to have fled the country.
EFCC chairman Nuhu Ribadu admits that it would be difficult to bring the runaway ex-governors to justice.
Orji Kalu says he has nothing to hide
"Our jurisdiction does not go beyond the boundaries of Nigeria, so if these people manage to run away from the country, it will be difficult to get to them," he told the BBC in a recent interview.
"But we do enjoy very cordial working relationship with the law enforcement agencies of some countries and those of the UK and the US, for instance, have been very helpful in this regard."
Mr Ribadu says his agency is investigating almost all the 36 former governors for alleged corruption.
The investigations ran into a legal brick wall while the governors were in power, as their constitutional immunity meant that they could neither be arrested nor prosecuted.
Now, stripped of this privilege, they have realised how legally vulnerable they are and have decided to stay as far as they can from the EFCC, which is often accused of being used to intimidate opposition politicians.
But one former governor who is not heading for the frontiers, yet, is Abia's Orji Kalu, who has decided to move to the capital, Abuja, after he handed over government to his ally Theodore Orji, who won the election from prison.
Mr Orji, who was being held by the EFCC on charges of money-laundering, was granted bail to attend Tuesday's inauguration in the south-eastern town of Aba.
Just like former President Olusegun Obasanjo handpicked Mr Yar'Adua as his successor, Mr Kalu picked his trusted friend to succeed him, in a move many see an attempt to cover the ex-governor's tracks and keep his financial deals in the state secret.
Mr Kalu says he has nothing to hide and will not run away like the others.