Applicants are lining-up to become the next undercover illegal brothel agent for a Sydney private investigation company.

Last week The Sun-Herald revealed how ratepayers were funding undercover operatives to have sex with prostitutes as a last resort to convince judges to close illegal brothels.

Mystery man: Fred Allen (an alias) who may soon face competition for work. Credit:James Brickwood

In the past three years a 60-year-old man from Lyonswood Investigations was hired by 10 Sydney councils to have sex with sex workers and help strengthen their legal case against underground operators.

After Lyonswood managing director Lachlan Jarvis revealed last week he was on the lookout for recruits more than 20 resumes arrived from men hoping to land the role.