Rio Tinto Group Chief Executive Officer Jean Sebastien Jacques said an investigation into the lawfulness of a payment made to an external consultant relating to a giant iron ore project in Guinea has “shell-shocked” the company and may take several years to resolve. The world’s second-biggest miner last week alerted authorities, including the U.S. Department of Justice and the U.K.’s Serious Fraud Office, to a $10.5 million payment made to Francois de Combret in 2011 for assisting negotiations with Guinea’s President Alpha Conde. An e-mail exchange discussing the payment shows former CEOs Tom Albanese and Sam Walsh, who was then head of Rio’s iron ore unit, were aware of the payment. “Many people across Rio Tinto are still shell-shocked,” Jacques said in an internal memo seen by Bloomberg News. “The day I was made aware of a potential issue we launched an investigation. It wasn’t a decision we took lightly. We will fully cooperate with the authorities. Their investigations may take several years.” The $20 billion Simandou project was once one of the world’s most prized mineral assets. It has been at the center of a power struggle for almost a decade having attracted some of the biggest mining companies, Israeli billionaire Beny Steinmetz and powerful advisers including investor George Soros and former U.K. Prime Minister Tony Blair. It’s also spawned many legal challenges and a U.S. grand jury probe into potentially corrupt payments to Guinean officials. Rio Tinto declined 0.3 percent to A$59.29 at 10:29 a.m. Tuesday in Sydney trading, as competitor BHP Billiton Ltd. fell 0.7 percent. A team of external lawyers undertook a “significant data collection and review exercise,” which led to the decision to alert authorities, Jacques said in the memo. Rio is restricted on what information it can release because the investigation is ongoing, said Jacques, who became CEO in July. “Some of us may be feeling that we are better informed by the press than by ourselves,” he said. “Speculation is running in some quarters and some of what is being said strikes at the heart of the culture and values of our company, which for me are fundamentally strong and vitally important.” Rio suspended key executive Alan Davies and said Debra Valentine, head of legal and regulatory affairs, stepped down in relation to the company’s inquiry over the payment. Davies, head of Rio’s energy and minerals unit, was accountable for Simandou at the time of the payment in 2011, the company said last week. He had been among internal challengers to become CEO ahead of the appointment of Jacques. Rio announced at the end of October that it was exiting the Simandou project and handing over its stake to partner Aluminum Corp. of China, known as Chinalco. That was before Rio said it informed authorities over the payment to the consultant. Development of Simandou and its estimated 2 billion metric tons of iron ore has been thwarted by numerous problems, including a slump in prices, corruption probes and the West African Ebola outbreak in 2014. There have also been difficulties in finding partners to fund the rail and port infrastructure component of the project expected to cost more than $10 billion.