By Ju-min Park

SEOUL (Reuters) - The starlet of a TV soap became the most talked-about celebrity in South Korea on Wednesday when a TV channel revealed President Park Geun-hye once used her name as a pseudonym at a beauty and detox clinic, a distraction from the scandal engulfing her administration.

Gil Ra-im, the heroine of the smash hit drama "Secret Garden", became the object of parody following the report that Park used her name at the Chaum beauty and anti-aging clinic in an upscale Seoul neighborhood.

Park is under intense pressure from an angry public to step down over allegations that she allowed a friend, Choi Soon-sil, to use her closeness to her to meddle in state affairs and exert improper influence in the cultural and sports communities.

Cable channel JTBC said late on Tuesday that Park frequented the clinic, even after she took office in 2013. Rhie Dong-mo, president of Chaum, confirmed that Park used the pseudonym Gil Ra-im in 2011.

"We can't deny patients who want to use pseudonyms," Rhie told Reuters by telephone.

The presidential Blue House declined to comment.

Chaum, where the enrolment fee is $130,000, offers anti-aging, detox, food therapy and spa services, according to its website.

"Secret Garden", about the life of a struggling stunt woman, Gil Ra-im, who falls in love with a rich department store owner, has aired in at least 14 countries around the world including China, Japan and as far away as Argentina.

In another twist, the Health Ministry said on Tuesday its probe of Chaum found prescriptions for an intravenous glucose and vitamin mix were issued for Park from 2012 to 2014 and a staff doctor had fabricated charts to record them as being issued for Choi and her sister.

A ministry official with direct knowledge of the probe said he was not aware of Park's use of a soap opera character's name but there was no plan to launch a new investigation.

(Editing by Jack Kim and Nick Macfie)