A group, which is unhappy at the moral nature of the website, has released the details of millions of people who had signed up to use it.
It's now claimed some employees at the Catholic Church in Rome were members, although Premier has been unable to independently verify the reports.
Anyone is able to sign up to Ashley Madison without email verification, meaning they could use any email address to set up an account, including fake ones.
Website Ashley Madison, which has the tagline "Life is short. Have an affair", was hacked last month by a group calling itself The Impact Team.
The hackers said they would publish what they claimed was a database of 37 million members and the information has been posted on the Dark Web, described as the ''underground of the internet'' or the ''internet black market''.
Avid Life Media (ALM), which runs Ashley Madison as well as dating sites Cougar Life and Established Men, said it is investigating the latest claims "to determine the validity of any information posted online".
In a statement ALM said: "Furthermore, we will continue to put forth substantial efforts into removing any information unlawfully released to the public, as well as continuing to operate our business.
"This event is not an act of hacktivism, it is an act of criminality. It is an illegal action against the individual members of AshleyMadison.com, as well as any freethinking people who choose to engage in fully lawful online activities.
"The criminal, or criminals, involved in this act have appointed themselves as the moral judge, juror, and executioner, seeing fit to impose a personal notion of virtue on all of society.
"We will not sit idly by and allow these thieves to force their personal ideology on citizens around the world. We are continuing to fully co-operate with law enforcement to seek to hold the guilty parties accountable to the strictest measures of the law."