Complaints made against police officers in Leicestershire have increased by 20% in the past year.
A report being presented to the county's Police Authority shows allegations of assault, unlawful arrest and oppressive conduct are all up on last year.
Over the eight months between April and December last year, the report shows 256 complaints were received - up from 203 in the same period in 2002.
Around 25% of the complaints were resolved without the need for full investigations - short of the force's target of 40%.
Chief Superintendant Paul Gibson, who is head of professional standards at the force, said the figures needed to be scrutined closely.
He told BBC News Online: "We are doing a fair amount of analysis on them. We have had one complainant who has made 13 separate complaints which has skewed the figures."
He said there had also been a number of complaints after a crackdown on anti-social behaviour in the Hinckley area.