The No. 2 boss at Yamaguchi-gumi, the nation's largest underworld syndicate, was arrested Thursday for allegedly extorting some ¥40 million from a man in Kyoto from 2005 to 2006, Kyoto police said.

The arrest of Kiyoshi Takayama, 63, from Kobe, was the result of a clampdown on his Kodokai gang before the release next spring of Yamaguchi-gumi don Kenichi Shinoda, who also hails from the Nagoya-based Kodokai, the dominant force in Yamaguchi-gumi.

Shinoda, known in the underworld as Shinobu Tsukasa, became the sixth don of Yamaguchi-gumi in July 2005. He was imprisoned in Osaka the following December on gun charges.

Takayama was arrested without incident during a 5 a.m. raid on Kodokai's Kobe base that found him in his residence on the premises. He has denied involvement in the extortion case, the police said.

Takayama allegedly extorted the protection money from a 65-year-old man in the construction business over three payments between December 2005 and December 2006, in conspiracy with Yoshiyuki Takayama, leader of another Yamaguchi-gumi-affiliated gang in Otsu, Shiga Prefecture. Takayama has already been indicted.

Although Takayama was not present at the scene of the incident, the police have determined that they can build a case against him because the victim was told by the gang members that the money would be delivered to "the boss in Nagoya," apparently referring to Takayama, they said.