They said this was based on seeing wedding rings on their fingers or baby seats in their cars.
The researchers interviewed 12 male prostitutes who worked in Phoenix Park, particularly around the Wellington Monument.
The study said factors that led to the individuals becoming engaged in the activity included “childhood sexual or physical abuse, leaving school early, running away from home and a dependence on heroin”.
The authors said there was a “high level of family dysfunction” among the participants.
* Five of the 12 reported sexual abuse, three of whom also experienced physical abuse.
* Four others reported physical abuse only.
* Three spoke of sexual abuse by members of religious orders.
* Five of their fathers were alcohol-dependent.
* Ten of the 12 were heroin addicts, while seven were dependent on alcohol.
The report, entitled Male Street Prostitution in Dublin, said the average age of leaving school was 14.
Ten of those interviewed had left the family home before they were aged 18. This was mainly because of stealing, drug use or sexual or physical violence.
Participants said they entered prostitution because they had exhausted other options of getting money. The average age of their first paid sexual encounter was 21.
All 12 said they used drugs while engaged in sexual activity. They charged between €35 and €100, depending on the activity and earned, on average, €240 a week.
However, these prices may have changed, as the survey was conducted some years ago.
In relation to their clients, the report said: “The estimate of married men as clients ranged from 40% to 95%, which was supported by reports of clients wearing wedding rings and having baby seats in their cars.”
Ten of the 12 said they were heterosexual.
Researchers said six had severe levels of depression, with three in this group reporting suicidal thoughts.
Of the other six, three reported moderate depression and three reported suicidal thoughts.
The report was published by Rutledge in the Journal of Homosexuality in 2011. It was conducted by six researchers, led by Dr Ian McCabe.
The report’s authors said their research was the fourth major study on male street prostitution in Ireland.
The research was made available in Ireland this month by the Health Research Board.