The leader said that while other female celebrities had used their fame to advocate the protection of women caught up in Thailand's sex trade, Rihanna chose to partake in it.
The fresh criticism about Rihanna and her Phuket visit to the sex show comes from Christian Film & Television Commission founder and chairman, Dr Ted Baehr.
Quoted in christiantoday.com, Dr Baehr praised 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.'
On the other hand, Rihanna tweeted to her 32 million followers about a female performer's obscene routine as part of the show in a Phuket bar.
Rihanna tweeted her surprise at the variety of animals and objects that were used by the female performer during the routine. She was also pictured on Instagram with a protected animal, a slow loris.
As a result of her tweets and the photograph, arrests of slow loris touts were made. Last weekend police arrested the owner of the bar.
Until Rihanna's tweet, police in the Phuket tourist hub of Patong had denied the existence of sex shows in a tourist walking street that officers patrol night and day.
The existence of sex shows - the arrested man is reported to run two - was denied despite the scores of touts who thrust notices offering lewd attractions into the faces of visiting families out for an evening stroll.
While genuine, Dr Baehr's viewpoint appears to lack a little reality.
He is reported as saying: "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.''
However, he did go on to say: ''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.''
No further tweets or photographs on either sex shows or slow lorises have been posted by the young singer as she continues a world tour.
Indeed, some of her own music videos have been rated as questionable and close to sex show material.
Whether Thailand needs to deal with its attempts to pretend there are no sex shows and no slow lorises being abused was raised today in an editorial in 'The Nation.'
The newspaper says of the reaction to Rihanna's tweets and photograph: ''For the local people, as well for expats who have been here long enough, officials were merely covering their own backs.''
''It is unfortunate that this social-legal predicament has to rest on the shoulders of a district chief and the Phuket police.
'Is it so hard to admit that the world's oldest profession and lewd sex shows are thriving in Thailand? Or that we sell counterfeit goods and trade in endangered species?
''If we could be more honest, we can debate these issues in a more meaningful way, and formulate concrete solutions to things such as corruption, extortion by the authorities and labor rights for sex workers.''