France's Interior Minister and presidential contender Nicolas Sarkozy has been accused of abusing police powers to recover his son's scooter.
Mr Sarkozy called the complaints against him "stupid"
Police carried out DNA tests to bring charges against three youths accused of stealing the scooter.
Mr Sarkozy, who says the complaints are "stupid", is under pressure to step down as minister to prevent a conflict of interest as he runs for election.
The first round of the presidential election is due on 22 April.
Centrist presidential candidate Francois Bayrou said the way the theft was handled showed France was a country of "double standards".
"This kind of thing happens every day in France, without warranting this kind of police deployment," he told French radio.
On Wednesday, Mr Sarkozy told French radio that 7,000 stolen scooters had been recovered last year.
"What, should DNA tests not be carried out, should a scooter not be searched for because it belongs to one of my children?"
A police officer, asked about the operation, said the case was handled using "classic methods", the AFP news agency reported.
Police officers received a report that a scooter belonging to Mr Sarkozy's son from his first marriage had been stolen outside the family home in the well-to-do Paris suburb of Neuilly on 7 January, a police spokesman said.
Ten days later, police on a routine patrol found the scooter while searching a basement for stolen goods in the rundown northern suburb of Bobigny, he said.
Police only used a DNA test to distinguish between suspects seen by a witness, he added.
Mr Sarkozy is already under pressure from the opposition Socialists to step down as interior minister.
The opposition Socialists have asked the country's Constitutional Council to rule on whether Mr Sarkozy could be a candidate and remain in his ministerial post.
An Ipsos poll due to be published on Thursday shows Mr Sarkozy has widened his lead over rival Socialist candidate Segolene Royal, giving him a second round victory over Ms Royal with 54% of the vote against 46%.
On Tuesday, Mr Sarkozy was in London to meet UK Prime Minister Tony Blair on his first foreign trip since announcing his presidential bid.