Forty-eight police officers are working for the Merseyside force - despite having criminal convictions.
According to the Freedom of Information Act, a total of 42 have convictions for motoring offences with 20 being for drink-driving.
The remaining six have convictions for various crimes including assault and being drunk and disorderly.
Since 2003 no convicted officers who have appeared at a misconduct panel have been allowed to remain in post.
Nine officers also had to resign following drink driving convictions when a ruling came into force in 1997 forbidding officers convicted of drink driving to work within the force.
Assistant Chief Constable of Merseyside Police Helen King said: "Many of the convictions held by serving officers are historic - we currently have 48 serving officers with criminal convictions.
"We expect the highest integrity from our officers and staff and require every individual to declare a conviction either during employment or on application to the job.
"If an officer is convicted of an offence and appears before a misconduct panel, a number of factors are taken into account.
"They include the nature and seriousness of the offence and any mitigating circumstances."