El Salvador's former president, Francisco Flores, tried to flee the country on Tuesday, according to the current president, Mauricio Funes.
Mr Flores is under investigation for allegedly misusing millions of dollars in funds from Taiwan, which he denies.
He rejected suggestions he was trying to escape to neighbouring Guatemala.
He has admitted receiving cheques worth $10m (£6m) from Taiwan during the last two years of his presidency, but says they were not for his personal use.
Mr Flores, who governed from 1999 to 2004, failed to appear before a congressional committee hearing into the alleged misuse on Tuesday morning.
According to President Funes, Mr Flores tried to flee to neighbouring Guatemala to avoid attending the hearing.
"At 11:00, ex-President Flores tried to leave the country in a vehicle at the La Hachadura crossing," Mr Funes said.
"He managed to get past the first control point unnoticed, until a border control officer noticed strange behaviour in his vehicle and stopped him, and made him and his driver turn back," Mr Funes explained.
Mr Flores said he had alerted the congressional commission to his planned absence, telling them he would be out of the country on business.
The commission scheduled him for a Tuesday afternoon meeting instead and warned that if he failed to appear again, it would send the police to find him.
Mr Flores attended the afternoon meeting insisting he had not attempted to flee the country.
"I did not leave the country. I did not hide. I decided at the border not to attend the meeting I had in Guatemala and I came back. That's why I'm here before you," he told the committee.
In previous hearings, Mr Flores said that he received three cheques from Taiwan totalling $10m.
He has maintained all along that such "donations", made out to the person soliciting the funds, were not unusual and that he passed on the money through the appropriate channels.
But President Funes has alleged that the money never reached the government programmes it was intended for, instead being deposited in a bank in the Bahamas.
Mr Flores says the investigation is politically motivated.