The married officer, in his 20s, was allegedly caught on covert cameras while entering the women's cells at night, The Sun reported.
The three women claimed they were given enhanced privileges in return for sex. Two of them actually believed they were in love with the officer.
Acting on a tip-off, prison bosses installed secret video equipment to gather evidence over many weeks.
Detectives were then called into the all-women Bronzefield prison, in Ashford, Surrey.
The officer was arrested at his home on suspicion of misconduct in a public office. He has since got bail.
He was sacked and Surrey Police is conducting a criminal investigation.
London: A prison officer at a jail in Britain was arrested and sacked after secret cameras caught him having sex with three women inmates, a media report said Sunday.
First Published: Sunday, December 16, 2012, 17:37