By Chris Hogg
BBC Taiwan correspondent
Taiwanese police investigating an apparent assassination attempt against President Chen Shui-bian earlier this year say they are chasing a suspect.
Mr Chen won re-election by a tiny margin
They say he is a man who may have carried out the shooting in an attempt to swing the vote in Mr Chen's favour.
The move follows the impeachment of several top security officials, who are accused of ignoring a tip-off about the man before the attack.
President Chen won re-election by a margin of less than 0.2%.
It is nearly four months since the attack on Taiwan's president and vice-president. Conspiracy theories abound, and the opposition has hinted at foul play.
But so far the police and the security services have failed to produce a suspect.
Now there is a suggestion that the security services were pre-warned about the shooting.
A report compiled by a government committee says a security bureau agent warned that a man he described as "a gangster-like" supporter of the president had threatened to shoot him.
The man hoped an attack would provoke a wave of sympathy for President Chen and swing the vote in his favour.
The agent said a newspaper reporter in the southern city of Tainan had tipped him off. But his superiors did not believe him.
A police spokesman in Tainan, where the shooting took place, said they were chasing a man but so far had made little progress.