Officers in the Metropolitan Police (Met) are moonlighting in jobs such as modelling, driving and childcare, police records have revealed.
By night, officers may be driving or modelling for extra cash
Up to 444 (1.5%) of police workers - from constables to deputy assistant commissioners - registered second jobs and business interests last year.
The Met said Home Office guidelines permit other business interests so long as they do not interfere with policing.
One police group said money from extra work helped pay home and family costs.
Other forms of work included hypnotherapy, bouncy castle hire, film extra work, massage, building, entertainment, photography, writing and floristry.
The most popular additional work was training (147 officers), driving (60) and consultancy (27), figures showed.
The statistics released under the Freedom of Information Act show in 2004 that 456 officers registered other jobs and business interests, while in 2003, there were 402.
A spokeswoman for the Police Federation of England and Wales said: "Many officers, particularly young officers, do need to take on extra jobs for financial security for their families.
"Over the last 10 years officers have seen the erosion of rent allowance, police houses and overtime - all of which helped with financial security."
She added that research was needed to find out how widespread moonlighting is within the force and whether it impacts on the service.
The Met has not commented on the figures.