WASHINGTON (CBS) — The House Ethics Committee has opened an investigation focusing on a trip Congressman Peter Roskam (R-IL) took to Taiwan in 2011.

The committee announced on its website Friday that it was extending its investigation of Roskam, and that the Office of Congressional Ethics – an independent, non-partisan group – had brought the matter to its attention.

The committee did not state the reason for the probe, but Roskam’s office indicated the case involved an eight-day trip to Taiwan the congressman and his wife took in October 2011.

“The record reflects that Rep. Roskam fully complied with all laws, rules, and procedures related to privately sponsored travel,” Roskam spokeswoman Stephanie Kittredge said said in a written statement. “ The trip was vetted and approved by the House Ethics Committee, the body legally authorized to make determinations on Congressional conduct. The OCE is wrong to take issue with the involvement of the Government of Taiwan in planning and conducting the trip, a matter that is routine, allowed under the law, and was known to the House Ethics Committee as they thoroughly vetted and approved the trip.”

Roskam, 51, represents a district that includes his hometown of Wheaton and other suburbs. He serves as the chief deputy whip for the House Republicans.

The committee said it would announce any action it takes against Roskam in September, and noted its decision to extend the investigation doesn’t indicate any proof an ethics violation took place.

“He fully expects the clear and indisputable facts of the case to speak for themselves, that both he and his staff have acted in accordance with all laws, rules, and regulations,” Kittredge said. “ Rep. Roskam and his staff have fully followed House Ethics Committee procedures to take an approved, appropriate, and informative trip to a key U.S. strategic ally.”

Watch & Listen LIVE