The service came to light earlier this month when a 24-year-old Tokyo woman died in hospital of cyanide poisoning, police said.

"The woman accessed the Internet site and purchased cyanide there," a police spokesman said.

The site offered medication to people who "do not know how to obtain the right drug" to commit suicide, police said, quoting the phrasing used by the Internet page.

The capsules were offered for delivery by parcel post for between 30,000 and 50,000 yen ($258 and $430).

Delivered by mail

Police said they found a parcel in the home of the woman, and contacted the sender, asking him if he knew the woman.

The man, a 27-year-old licensed pharmacist from Sapporo, then called the hospital where the woman was taken after ingesting the cyanide, police said. When he found out that she had died, he killed himself.

According to the police, the names of six other customers were found through an investigation of the man's banking records.

One of them, a 21-year-old Tokyo woman, also committed suicide, although she did not use the cyanide capsules - she took a lethal dose of sleeping pills prescribed by her doctor, police said.

Police have confirmed that three of the customers have not taken the cyanide, but they are still trying to track down two other customers of the website.