The son of Nigeria’s former dictator Sani Abacha, Abba Abacha, will face a new trial in Switzerland starting July 4 on charges of participation in a criminal organisation that raided public funds, his lawyer said Friday.Abba’s lawyer, Christian Luescher, told Swiss news agency ATS that his client wanted to come to Geneva to attend the trial.During a previous trial in 2010, Abba did not attend as he was unable to obtain a visa. The court convicted him in absentia, handing down a two-year suspended prison term and confiscating his assets.But he won an appeal over procedural irregularities and the fact that he was unable to obtain a visa in time. The Swiss Federal Tribunal therefore ordered the sentence annulled and a retrial.If he is unable to get a visa this time, the new trial would be delayed.Abba, 43, denies all charges.Sani Abacha took over power in 1993. Until his death in 1998, he siphoned off an estimated more than $2 billion from the country’s central bank, including $700 million that was deposited in Swiss banks. Nigeria later recovered that amount.