OSAKA -- A close friend of the scandal-tainted former mayor of Higashi-Osaka killed himself over the weekend after having been questioned by investigators over the receipt of illegal favors from the mayor, it was learned Monday.

The 68-year-old pharmacy owner, whose name was not provided, committed suicide Saturday at a hotel in Wakayama Prefecture. A note found at the scene that was addressed to his family that read, "Sorry for troubling you," police sources said.

The man purchased a plot of land next to the city's new hospital in September -- six months before the municipality officially decided to have private pharmacies prepare drugs in accordance with prescriptions issued by the hospital, the sources said. The man opened a pharmacy on the site in April.

Investigative authorities had been questioning the man on suspicion that he was offered favors by former Mayor Yukio Shimizu. Shimizu, 64, has been behind bars since late April for having his girlfriend illegally receive benefits from the city's pension program.

According to Kyodo News, the man had earlier admitted that he and Shimizu had enjoyed a close companionship for over 10 years and that the mayor was a frequent customer of the restaurant run by the man's wife, one of the leading members of the association of Shimizu's supporters. The man had denied wrongdoing in connection with his new pharmacy by claiming, "I have clean hands."