A Nigerian court of appeals has freed a former Mtel CEO and three others accused of receiving bribes from Siemens.

The German telecom equipment maker company is alleged to have paid more than US$100 million in bribes to officials in Nigeria, Libya and other countries in order to win supply contracts.

Global suppliers including China's Huawei Technologies and ZTE are seriously competing for contracts in the region. There have been a number of cases over the last few years in which senior government officials and managers of telecom companies have been accused of offering bribes to win telecom equipment contracts.

In 2007, the Nigerian government canceled a supply contract with Siemens and suspended dealings with the company pending investigations into allegations that it gave more than $14 million in bribes to Nigerian government officials in order to be offered a supply contract.

One of the accused is the former CEO for government-owned mobile telecommunications company Mtel, Edwin Moore Momife. The other three are the former director of the Power Holding Company of Nigeria, Maigada Shuaibu; former general manager of finance at Nigerian Telecommunications (Nitel), Emmanuel Chukwuemeka Ossai, and former permanent secretary at the Federal Ministry of Power and Steel Mahmood, Sadiq Mohammed.

In its ruling, the court of appeal said the country's Economic and Financial Crimes Commission (EFCC), failed to establish a lawful case against the accused.

Justice Tinuade Akomolafe Wilson, who read the judgment said, "Momife and the three other accused had no case to answer because the Siemens officials implicated in bribery case as conspirators were neither charged nor declared wanted in Nigeria."

The court held that the main accused person, Momife, "could not have conspired with himself to commit the alleged crime."

The court said in order to establish a case against Momife and the other accused, the EFCC could have taken the officials to court with Siemens officials who allegedly bribed the accused.

The ruling by the appeals court effectively overturned the decision of the High Court that earlier found all four of the accused guilty of bribery. Momife and the other accused officials were detained by the court but later released on bail. They appealed the decision of the High Court.

Momife and his co-defendants were also accused of having received for themselves and their family members air tickets to attend the FIFA World cup in Germany in 2006 in addition to receiving frequent sponsorship to Germany for medical check-ups.

Momife admitted having received air tickets from Siemens but the court said it found no evidence of a relationship, business or otherwise, between Siemens and the accused.

In 2007, Siemens was indicted by a court in Germany for paying bribes to government and officials in African countries including Cameroon, Libya and Egypt in order to win supply contracts, It was slapped with a fine of about $201 million.

Siemens accepted responsibility for misconduct and provided names of bribe recipients. The EFCC asked for a certified copy of the Germany court's judgement in order to help it identify the people who were involved in the bribery and how much was given to them. It is not clear whether the copy of the judgement was given to EFCC by the Germans.

In 2010, the World Bank, as a major funder of Information and Communication Technology (ICT) projects in Africa, imposed a two-year bidding rights ban on Siemens because of the company's alleged corruption in Africa's telecom sector.

Siemens has since committed to paying $100 million to support global efforts over the next 15 years to support anti-corruption efforts.

In addition to agreeing to change industry practices, clean up industry procurement practices and engage in a collective action with the World Bank to fight corruption and fraud in the telecom industry, Siemens also agreed to provide information on any additional cases of wrongdoing to the World Bank's integrity vice presidency, which investigates fraud and corruption.