The Fair Trade Commission has launched an investigation into the country’s seven top-rated hotels in Seoul on suspicion of colluding to rig the prices of their wedding packages and rooms, according to industry sources and reports Thursday.

The seven hotels are Lotte Hotel Seoul, Lotte Hotel World, The Shilla Seoul, The Westin Chosun Seoul, Sheraton Grande Walkerhill, W Seoul-Walkerhill and The Plaza Hotel Seoul.

“FTC investigators requested yesterday documents related to our wedding business,” an official at a five-star hotel said, asking not to be named due to the sensitivity of the subject.

The hotels boast they facilitate often onerous wedding planning by offering comprehensive packages that come with the ceremony, reception, catering, floral design, photography, cakes, entertainment and more.

The probe, however, comes on the heels of mounting complaints from customers who claimed the hotels charge tens of thousands of dollars for a service worth a few thousand dollars, like flower decorations.

Prices of a wedding package for 500 attendees hover between 70 million won ($62,600) and 139 million won, industry figures show.

Further, the antitrust body is examining whether the luxury hotels forged backdoor deals to raise room rates, Yonhap News reported.

An official at the FTC said he “cannot comment on any ongoing investigation.”

An official at a luxury hotel said it is “rather difficult to run a price-fixing cartel because room prices are set according to occupancy rates, which vary by hotels, and it’s all shown on our website in real time.”

In general, a room at a five-star hotel in Seoul costs at least 200,000 won per night on weekdays and more than 300,000 won on weekends.

A one-night stay in a double room from March 22 fetched 330,000 won at Lotte Hotel Seoul, its website shows. Westin Chosun charged 380,000 won for the same, while Sheraton Grande Walkerhill was at 210,000 won.

“I and my husband paid 480,000 won for just one night at W Seoul to celebrate our first wedding anniversary last year,” said a 28-year-old company employee surnamed Yoon.

“The room, breakfast and services were all nice but I still felt it’s overrated. I don’t think I’ll make the same choice this fall.”

By Shin Hyon-hee (heeshin@heraldcorp.com)