OSAKA -- A letter containing a white powdery substance was delivered Tuesday to the office of scandal-tainted former lawmaker Kiyomi Tsujimoto in Takatsuki, Osaka Prefecture, police said.
The letter appears to have been a prank, investigators said, adding they are examining the substance.
A female staff member who found the letter was checked at a hospital but evidenced no abnormalities, according to Tsujimoto's office.
The letter was among about 30 items of mail delivered Tuesday evening.
Tsujimoto, a former policy chief of the Social Democratic Party, resigned as a House of Representatives member last month over a pay misappropriation scandal.
After a number of deadly anthrax attacks and scares in the United States last year, many prank cases have occurred in Japan with similar whitish powdery substances.