The ruling Liberal Democratic Party on Thursday sent an inspection team to visit U.S. beef processing facilities after beef parts banned under an agreement that partially reopened the Japanese market to U.S. exports were discovered last month in a shipment from New York.

The five-member team, headed by Toshikatsu Matsuoka, former senior vice farm minister, will visit meatpacking plants, including a Tyson Foods Inc. plant in Kansas, and return home Monday, according to LDP officials.

The major U.S. meatpacking facility was visited earlier by a fact-finding mission of the Democratic Party of Japan, the country's largest opposition party.

After returning to Japan, the DPJ team claimed prohibited high-risk parts were not completely removed from beef at the facility, which triggered a strong protest from Tyson Foods.

Tyson Foods has urged the DPJ to retract the claim and apologize to the company.

U.S. Agriculture Secretary Mike Johanns also faulted the DPJ's remarks.

In a speech in Sakai, Osaka Prefecture, the previous day, LDP Secretary General Tsutomu Takebe voiced displeasure with the DPJ's inspection team, saying, "A dispute has erupted over whether (the DPJ's) investigations were carried out in a sincere and fair manner."

Takebe said conflicts over the matter are developing into a major diplomatic issue.

On Dec. 12, Japan partially lifted a two-year-old ban on U.S. beef imports imposed in December 2003, following the discovery of the first U.S. case of mad cow disease.

Tokyo reimposed the ban on Jan. 20 after banned spinal cords were found in a shipment of beef from the U.S.