Renowned South Korean artist Lee U-fan confirmed Thursday once again that he did paint all 13 paintings that are suspected of being forgeries.

In a press briefing in central Seoul, the artist said the paintings in question were his work beyond a doubt.

"I checked them with my own eyes and they are certainly all mine judging from their breath, rhythm and colors," the artist said.

He continued: "Breath and rhythm are like fingerprints, which no one can copy. A third person, however talented the person might be, can't do exactly like the artist does.

"An artist would know if a certain painting is an authentic work of his or hers within a minute. My paintings, in particular, are very simple so it is easily noticeable if not authentic."

He made the same argument on Wednesday when he appeared at the

Seoul Metropolitan Police Agency for an investigation.

Police began looking into the forgery scandal last year when they were tipped off from someone in the art circle that counterfeits of Lee's signature paintings such as "From Dots" and "From Lines" worth billions of won or millions of US dollars had been circulated in galleries in Seoul's Insa-dong neighborhood from 2012 to 2013.

They have since arrested the owners of the galleries suspected of circulating the alleged counterfeits and commissioned the National Forensic Service and civilian experts to analyze whether the 13 works they seized from the galleries are forgeries or not.

Both sides then confirmed them as counterfeits after comparing them with six of Lee's authentic works.

Earlier this month, a 66-year-old gallery owner was indicted on forgery and fraud charges for allegedly earning 1.3 billion won by selling counterfeits of three of Lee's works, including "From Point." The man identified by his surname Hyun admitted to having forged the paintings during police questioning.

Lee said, however, he immediately knew that those paintings were his during his first visit to police, but he took some time just in case. The next day, he came back to police and told them that all the 13 paintings were his work.

He vented his frustration on the way the police investigated the on-going forgery scandal. He said he was only able to see the paintings by himself nearly a year after the police had launched the investigation despite his repeated requests to do so.

"When the artist is alive, his or her opinions should be given priority, which is common sense in other countries. I can't really understand why police ignored this and asked ambiguous experts and the National Forensic Service to verify the authenticity. Moreover, they released the investigation result to the press first, not me."

Lee also claimed that police tried to make a deal by telling him to admit that four of the works are forgeries. He said police made his lawyer leave the room in the process, closeting him with an investigator.

Police immediately denied Lee's claim, saying they only tried to persuade him to be honest, free from his prestige as an artist.

They said a one-on-one talk is an often used tactic to draw sincere statements from a testifier.

"I asked Lee to have a private conversation as I wanted to hear honest words," said the investigator who was in charge of the interrogation. "I thought there could be some external pressure put on him as he said all the works are genuine articles just 10 seconds after looking at them."

During the briefing, Lee said "I am the painter" several times in frustration.

Asked about the presence of serial numbers, he said, "I was so poor at that time and my paintings weren't in high demand. I didn't put a serial number on each painting. All I did was paint." (Yonhap)