The authorities in Kenya are seeking to retrieve at least $1bn (£570m) siphoned out of the country by former officials.
Kenyans voted for the opposition coalition Narc at last year's elections
A six-month inquiry by investigative group Kroll has tracked the stolen money to accounts in big-name banks, and shares in London hotels.
The money may already have passed on to less co-operative places such as Zimbabwe, Kenyan ministers believe.
But experts say recovering the loot - possibly as much as $4bn - could be much more difficult than tracing it.
The money in question is thought to have been embezzled during the previous administration of former President Daniel arap Moi, who ruled for 24 years before stepping down following election defeat in December last year.
"Identifying the assets is just the first step," Gladwell Odieno, Executive Director of anti-graft group Transparency International (TI) Kenya, told BBC News Online.
"Getting the money back is a much more questionable proposition. The people who got the money out obviously had enormous resources, and it's not easy for developing country governments to conduct these cases.
"The odds are stacked against them."
If the money is still in Europe, then freezing it may still be possible with such means as the Mareva Injunction - a legal tool which allows assets to be frozen without the target being notified in advance.
But Justice Minister Robinson Githae told the BBC that the money may already be elsewhere.
"What we have been told is that this money, most of it, was in Switzerland, in Monaco and in the Cayman Islands," he said.
"But now the intelligence information we have is that this money is now being moved to some African countries like Zimbabwe, South Africa and Botwsana."
Mr Githae said scams during the 1990s included one where the government was allegedly defrauded of millions of dollars worth of official payments designed to encourage exports.
A massive public inquiry is now examining the allegations, one focus of which is a company set up in the early 1990s to encourage gold and jewel exports called Goldenberg International.
Other alleged scams involved government officials allowing their associates to borrow money from the central bank only to re-lend it at much higher interest rates.
The total figure for corruption has been put as high as $3-4bn, according to testimony to the inquiry into Goldenberg.
Such a large sum, the inquiry heard, could have funded universal primary education for a decade - and is not far off the entire government budget for the current year.
"Kenyans are seeing what they have lost, the years of development that have been stolen from them," Ms Otieno said.
Among those targeted by the investigation are a number of serving and former officials and ministers, who served under former President Daniel arap Moi, and Kenyans are expecting them to face sanctions when the inquiry reconvenes in January.
Mr Moi relinquished power after 24 years at the top after his Kanu party lost an election in December 2002.
A coalition of opposition parties, Narc, took over, and new President Mwai Kibaki put John Githongo - Ms Otieno's predecessor at the head of TI Kenya - in charge of ethics and anti-corruption.
In this case, the resources allegedly diverted as part of the Goldenberg International operation ended up in European and US banks.
Foreign exchange transactions at a number of banks, named at the inquiry in Nairobi, helped launder the proceeds.
According to the Financial Times, they also funded the purchase of assets including shares in two London hotels, the Kroll investigation has found.
In the future, it could be easier to recover this kind of money.
On 9 December the United Nations formally unveiled its International Convention against Corruption, signed by a number of countries including Kenya and the UK.
The Convention commits signatories to repatriate resources looted in this manner.
But it will not come into force till 30 countries ratify it, a process which could take at least two years.