Smallville actress Allison Mack, who is accused of sex trafficking and conspiracy to commit forced labor

Smallville actress Allison Mack reportedly tried to lure high-profile feminists Emma Watson and Kelly Clarkson into her disturbing sex cult in a series of ominous tweets.

The 35-year-old is accused of recruiting slaves into the secretive Nxivm cult before its founder Keith Raniere allegedly subjected them to humiliating acts.

Raniere's and Mack's initials were branded onto the pelvic area of women who joined the organisation, which has a large base in Albany, New York.

Now it has emerged Mack tried to recruit Harry Potter actress Watson, 28, and singer Clarkson, 36, both known for championing feminism and supporting women's rights, into the degrading cult.

Mack reportedly tweeted the pair about an 'amazing women's movement' and invited them to have a 'chat' with her about it.

'I'm a fellow actress like yourself & involved in an amazing women's movement I think you'd dig,' Mack wrote to Watson in January 2016. 'I'd love to chat if you're open.'

Emma Watson and Kelly Clarkson (right) were approached by Mack online and allegedly asked to 'chat' with her about her an 'amazing women's movement'

The next month she tweeted the star again, writing: 'I participate in a unique human development & women's movement I'd love to tell you about.'

Three years earlier she wrote to Clarkson: 'I heard through the grapevine that you're a fan of Smallville. I'm a fan of yours as well!' she wrote. 'I'd love to chat sometime.'

Several members of the cult reportedly held wild parties on billionaire Richard Branson's private Caribbean island.

The disturbing goings-on inside the organisation was exposed after two former members, known as Jane Doe 1 and Jane Doe 2, spoke out.

.@EmWatson I'm a fellow actress like yourself & involved in an amazing women's movement I think you'd dig. I'd love to chat if you're open. — Allison Mack (@allisonmack) January 24, 2016

.@EmWatson I participate in a unique human development & women's movement I'd love to tell you about. As a fellow actress I can relate so... — Allison Mack (@allisonmack) February 19, 2016

@kelly_clarkson I heard through the grapevine that you're a fan of Smallville. I'm a fan of yours as well! I'd love to chat sometime. — Allison Mack (@allisonmack) July 20, 2013

Mack referred to herself as Raniere's 'slave' and he as her 'master'.

She has been serving as leader of the cult since Raniere, 53, was arrested in Mexico, where many high-profile members fled earlier this year.

They both deny federal charges of sex trafficking and conspiracy to commit forced labor.

The allegations against Raniere and Mack were outlined in the Complaint and Affidavit in Support of Arrest Warrant that was filed back on February 14.

Keith Raniere, 53, led the secretive Nxivm cult. He was arrested in Mexico and is being held without bail ahead of his trial

US Attorney Richard Donoghue said in a statement: 'As alleged in the indictment, Allison Mack recruited women to join what was purported to be a female mentorship group that was, in fact, created and led by Keith Raniere.

'The victims were then exploited, both sexually and for their labor, to the defendants' benefit.

'This Office and our law enforcement partners are committed to prosecuting predators who victimize others through sex trafficking and forced labor.'

Mack has filed an application for an Order of Excludable Delay requesting that her trial begin after May 3. She stated that her legal team were in plea negotiations.

She is yet to comment on the allegations.

Raniere is being held without bail after the US attorney's office told the court the cult leader previously had sexual relationships with two minor females aged 15 and 12.

He and Mack are facing possible life sentences behind bars.