A second Hollywood actress has been identified as an alleged member of a sinister sex cult.

Battlestar Galactica star Nicki Clyne is said to belong to the DOS cult - a sinister organisation that brands its members with the initials of their leader, Keith Raniere.

DOS is said to be a secret society for the highest ranking female members within the self-help group NXIVM.

Battlestar Galactica star Nicki Clyne is said to belong to the DOS cult - a sinister organisation that brands its members with the initials of their leader, Keith Raniere

DOS members are branded with a symbol that reportedly includes Raniere and Mack's initials

Clyne's alleged membership of the organisation was reported by Sun Online, which also claimed to have seen a stash of pornographic images that are used to blackmail followers tempted to leave.

Clyne is believed to have been one of those who handed over pornographic material in a bid to prove her loyalty.

Clyne did not respond to Sun Online's requests for comment. There is no suggestion that Clyne was involved in any abusive behaviour. MailOnline has contacted her.

Last month, the New York Times broke the story about the secret sorority, which it claimed puts its female members on starvation diets and beats them if they don't recruit enough 'slaves'.

To outsiders, NXIVM is just a run-of-the-mill self-improvement group, offering classes that teach the answers to living a successful and fulfilling life.

But ex-members told the Times that NXIVM functions as a cult for people at the high levels of the group, who have dedicated themselves full-time to founder Keith Rainere and his teachings.

Last week, a former spokesman for the group, Frank Parlato, told The Sun that an 'Emmy Award-winning actress' is a 'key recruiter' for DOS.

While The Sun did not name the actress, DailyMail.com revealed she was Allison Mack, who played Clark Kent's sidekick Chloe Sullivan on the long-running CW series Smallville.

Allison Mack, right, a former star of the long-running Smallville TV series is reportedly a high-ranking member of the sex cult

Catherine Oxenberg's (left) daughter India (right) is reportedly one of the members of the cult

Parlato goes into further detail about Mack's role in the group on his blog, The Frank Report, which has been publishing information on the group's inner-workings.

(Parlato says he was fired after one year when Raniere caught him investigating the company's financial records. He has been locked in a legal battle with both Raniere and two Bronfman heiresses who are members of the group, the later of whom claim he defrauded them).

The Frank Report claimed that Mack created DOS with the intention of turning it into a worldwide organization that would be a 'force for good and a female force against evil'.

The former spokesman, Frank Parlato, says that Mack introduced corporeal punishment to the society, called DOS

Ex-members have detailed how only the most loyal NXIVM female members are offered the ability to try out for DOS.

In order to join, prospective new members must allegedly turn over damning personal information as a show of trust.

But ex-members say that information is actually used to keep members from speaking out about the horrifying reality of the group.

DOS operates as a master-slave hierarchy, with Raniere at the top and Mack as his immediate subordinate.

From there, Mack has several slaves of her own who are then ordered to recruit a group of slaves themselves, and it spreads down from there like a pyramid scheme.

Women in the group are allegedly kept on a 500- to 800-calorie a day diet because Raniere likes thin women and believes fat 'interferes' with his energy levels, Parlato claims.

DOS members are branded with a symbol that reportedly includes Raniere and Mack's initials (above, ex member Sarah Edmondson shows hers)

Slaves must immediately answer their masters any time they text or call them, and if they do not recruit enough slaves of their own, they are beaten with a paddle on their buttocks.

The Frank Report alleges that it was Mack who introduced corporeal punishment to the group.

When women are deemed worthy to enter the group, they are ordered to strip at an initiation ceremony and then branded with a symbol that includes both Raniere and Mack's initials.

The blog also says that there's yet another tier of the cult above DOS. Women who perform well in DOS may also be invited to join Raniere's harem.

Mack 'has assumed the top position in the harem,' the Report says.

'Miss Mack has proven capable in the recruitment department replacing many aging harem members with younger, more nubile women,' the Report says.

DailyMail.com reached out to Mack's spokesman for comment, but learned 'she is not taking press inquiries at the time'.

NXIVM said in a previous statement: 'The allegations relayed in the story are built upon sources, some of which are under criminal investigation or already indicted, who act as a coordinated group. We will explore any and all legal remedies to correct these lies.'

Mack has not been secretive about her work with Raniere.

Former Dynasty star Catherine Oxenebrg (left) says her daughter India (right) is being blackmailed by the cult

On her personal website, she details how Raniere 'mentored [her] in her study of acting and music' over the course of several years.

'As such, she has developed a deep connection to the nature of humanity as it relates to acting as an art form, and a tool for personal evolution,' the website states.

She also boasts that they partnered together in 2013 on a project to develop a curriculum taught in a private arts academy.

In a widely-circulated interview with Raniere, Mack is actually the woman asking the questions. In the video, she beams at Mack as he espouses his ideas.

Mack appears to have mostly quit acting. The last roles she had were on TV in 2015.

Before starting NXIVM, Raniere helped run Consumers' Buyline Inc, a company which offered members discounts on groceries and other products.

In the mid-1990s, the company was under investigation as a possible pyramid scheme.

It was shut down before any charges could be filed.

Investigators appear to be focused on bringing down his latest venture.

Earlier this week, former Dynasty star Catherine Oxenberg met with prosecutors in NY Attorney General Eric Schneiderman's office to speak about her daughter India, who is a member of the group, the New York Post reported.

Oxenberg has been outspoken about the group, and fears that her daughter is being starved and blackmailed.

According to the Post, Schneiderman's prosecutors are focusing their efforts on the women who were branded against their will.