The Metropolitan Police has spent thousands of pounds reviewing internal
security, after two employees accessed sensitive information from computers.
Civilian staff Sunshes Pike-Williams and Davina Kirwan admitted misconduct at Stoke Newington Police station, north London, between 2001 and 2002.
On Tuesday, Southwark Crown Court heard how the women's boyfriends were known to police and had criminal convictions.
The pair were suspended from their jobs and are due to be sentenced on 13 July.
Kirwan, 21, of Leytonstone, and Pike-Williams, also 21 and from West Ealing, both joined the force in January 2001.
Violence and firearms
The court heard how the pair accessed police computer databases and carried out hundreds of checks on different people, vehicles and crime reports.
They pleaded guilty to committing misconduct in a public office.
Det Supt Trevor Smith from the City of London Police specialist crime unit said there was "no direct evidence that they (their boyfriends) have benefited from this".
"Because of their actions, we had to conduct a long, lengthy and expensive
investigation, and we had to review methods and techniques that we were using," he said.