The leader of a Christian entertainment ministry has questioned Rihanna's decision to watch an illegal sex show during her Thailand tour.

Last month Rihanna tweeted to her 32 million followers about a female performer's obscene routine as part of the show in a Phuket bar.

The Guardian newspaper this week reported that her tweet "embarrassed Thai officials" and has since led to three arrests, including the owner of the bar who officials had been unable to apprehend until now due to lack of evidence.

Two other men were arrested last month after Rihanna posted a photo of a slow loris, a protected primate, on her social media sites, causing authorities to swoop in on wildlife dealers in the region.

Following her visit to the sex show in Phuket, Rihanna tweeted her surprise at the variety of animals and objects that were used by the female performer during her routine.

However, Christian Film & Television Commission founder and chairman, Dr Ted Baehr, felt Rihanna should have been thinking more about the way many sex show performers are abused.

He said: "Most times these female show performers are held in captivity against their will and are sold into slavery at such young ages they don't live past the age of 20, due to working conditions and highly-addictive drugs used to keep them enslaved."

Dr Baehr is disappointed that while other female celebrities have used their fame to advocate for the protection of women caught up in Thailand's booming sex trade, Rihanna chose to partake in it.

He praised the likes of American actresses Eva Mendez and Meg Ryan, who last year travelled to sex trafficking hotspots to expose the horrors of the trade in PBS documentary, "Half the Sky".

"It's not a victimless crime," he said. "In this case, Rihanna is a perpetrator. Our hope is that she will realise the severity of this global issue and get involved in the fight to promote human dignity and freedom."