Environmental and social justice groups on Wednesday condemned Italy's anti-corruption laws as "unfit for purpose".
The condemnation followed the acquittal of oil multinationals, Shell and Eni, on international corruption charges in Milan.
PREMIUM TIMES reported how officials of the oil companies were acquitted by the court Wednesday.
Thirteen other defendants in the case were also found not guilty.
But activists and anti-corruption advocacy groups monitoring the case expressed their disappointment in the verdict in a statement Wednesday night.
"The judgment brings shame on Italy," says Lanre Suraju of HEDA, a Nigerian anti-corruption group that was among the first to expose the corruption allegations surrounding the OPL 245 deal.
"One court has found the intermediaries of the OPL 245 deal guilty of international corruption, yet this court has found Shell and Eni not guilty. We await the full ruling of the Milan court to explain this bizarre outcome."
The two oil companies had been on trial in Milan since 2018, relating to their 2011 purchase of an offshore Nigerian oilfield, "OPL 245".
Shell and Eni agreed to pay $1.3 billion for the license to explore the field. $1.1bn of the company's payment was to be paid to Malabu Oil and Gas, a company controlled by Nigeria's former Oil Minister, Dan Etete.
Mr Etete had awarded his own company the license while in government. The Milan Prosecutor had alleged that the $1.1 billion paid by Shell and Eni was used to pay bribes to Nigerian politicians and kickbacks to managers at Eni.
"This is a dismal judgment that reflects the dismal state of anti-corruption legislation in Italy," said Antonio Tricarico of Re:Common, one of the groups whose complaint led to the Milan Prosecutor's investigation.
"If allowed to stand, it creates a terrible precedent for the global fight against corruption and the ability to hold multinationals to account."
Barnaby Pace, Senior Campaigner at Global Witness said: "Today's legal verdict is a disappointment but it will not stop us in our unrelenting quest to ensure accountability in the fossil industry. We urge the Milan prosecutor's office to consider all options for an appeal and believe that this verdict shows just how hard it is to hold the fossil fuel industry to account.
"Two middlemen have already been found guilty for their role in this deal in a separate trial. A criminal trial of Shell and Eni's Nigerian subsidiaries is ongoing in Nigeria while they also face an investigation in The Netherlands where Shell has said they expect to face criminal charges. Today's verdict does not mark the final word in this scandal for Shell and Eni."
In their joint statement, the campaigners warned that shareholders should not take comfort from the Milan ruling.
Several trials are also ongoing in Nigeria, where Eni and Shell subsidiaries have denied charges of official corruption and conspiracy to commit official corruption. Eni's CEO Claudio Descalzi is among several Eni executives currently under investigation over alleged obstruction of justice around the OPL 245 case where prosecutors have alleged he attempted to "pollute the process" of his own trial.
"This is a case that will not go away, ensuring that Eni's and Shell's OPL 245-era underwear will continue to be washed in public for years to come, says Nicholas Hildyard of The Corner House, a UK environmental justice group.
"For shareholders hoping Shell and Eni will ride off from Milan into a sunlit future, the prospects are of continuing controversy, potential convictions and headlines that link the companies to bribery, albeit bribery that is denied. For the companies, OPL 245 will remain an albatross around their necks."
On Wednesday, Re:Common, HEDA, Global Witness and Corner House called on the Milan Prosecutor to appeal the Milan Court's verdict.