The former presidential spokesman who was dismissed over sexual assault accusations admitted last week to touching the buttocks of the alleged victim during an internal investigation by the presidential office Cheong Wa Dae, an action he later denied, officials said Sunday.

According to Cheong Wa Dae officials, Yoon Chang-jung contradicted himself at Saturday's press conference, where he denied all sexual harassment allegations that led to his dismissal.

Yoon was fired on Thursday in Los Angeles, the last stop for President Park Geun-hye during her first visit to the United States, after allegations surfaced that he had sexually assaulted his temporarily-hired assistant in Washington. Yoon returned home from Washington without accompanying the president to the West Coast.

A police report obtained by Yonhap News Agency states that the woman told U.S. police that Yoon "grabbed her buttocks without her permission" Tuesday night at a hotel bar near the White House. The woman, a 21-year-old Korean-American, had been recruited by the South Korean Embassy in the U.S. to assist Yoon during the presidential visit.

On Saturday, Yoon held a press conference in Seoul and denied the sexual assault allegations. He claimed that he'd only patted the alleged victim on her waist in encouragement, and blamed cultural differences between South Korea and the U.S. for causing a misunderstanding between him and the woman.

However, the officials said Yoon had testified to Cheong Wa Dae officials that he had touched the woman's buttocks. They added that Yoon signed a document containing his responses from the questioning session.

Also according to the officials, Yoon admitted during the Cheong Wa Dae questioning that he had not been wearing his underwear when the woman visited his hotel room Wednesday morning.

However, at his press conference Saturday, Yoon explained that when the woman knocked on his door early in the morning, he rushed to open it while still in his underwear, believing someone had brought him an urgent message. When he saw the woman, Yoon claimed he told her to leave immediately and closed the door.

According to the officials, Yoon denied allegations during the Cheong Wa Dae investigation that he'd asked the woman to have sex with him and that he'd verbally abused her.

At his press conference, Yoon explained that he had taken the woman and his driver out for a drink Tuesday night. He said he had scolded the woman for causing delays to his schedule and had wanted to cheer her up by the day's end.

He also claimed the woman sat at the opposite side of a long table and the driver sat to his right, and that it was physically impossible for him to sexually assault her.

A South Korean Embassy official in Washington said Saturday, however, that the driver may not have been present for the whole time at the bar, adding, "(The driver) does not know everything that happened, and as far as I know, he did not say he witnessed the scene in question that happened in just an instant." (Yonhap News)