In a statement issued as his trial in absentia began, Mr Ben Ali said he had taken his family to Saudi Arabia for safety.
Mr Ben Ali said he had intended to return to Tunisia immediately, but the plane left without him, “disobeying my instructions”.
He flew to Saudi Arabia on 14 January following a popular rising.
“I was duped into leaving Tunis,” Mr Ben Ali said.
He also denied giving orders to fire on demonstrators, something he said could be proved through recorded contacts between the presidency, the interior ministry and other ministries.
But the BBC’s John Leyne says that for the moment that is not what he is charged with.
The current trial is looking at accusations of corruption and drug smuggling, all of which the former president also denies.
He faces up to 20 years in prison if convicted on various charges.
His lawyers said the trial was an attempt by Tunisia’s interim government to divert attention from their failure to restore stability in the country.
The Saudi authorities have yet to respond to an extradition request from Tunisia for Mr Ben Ali and his wife, Leila Trabelsi, and there seems little likelihood of them being brought to justice in person.