OSAKA — Police questioning a 56-year-old man arrested Friday afternoon for alleged attempted blackmail of Santen Pharmaceutical Co. found the suspect had no personal ties to the leading eyewash maker.

Police also said that the suspect, Takeshi Maeda, unemployed, told them that the blackmail scheme occurred to him when he saw an eye dropper in his house.

Maeda, from Kadoma, Osaka Prefecture, was arrested on suspicion of sending a bottle of doctored Santen eyewash to the company and demanding 20 million yen from the Osaka-based maker.

Maeda has reportedly told police that he needed money because he had several hundred thousand yen in debts.

Santen, which received the extortion letter June 14, recalled 2.5 million bottles of eyewash — worth 300 million yen at production cost — from the market and destroyed them June 17.

Investigative sources said Santen received an apology letter that bears Maeda’s handwriting several days ago, expressing sorrow for causing “an uproar” following the blackmail attempt.

“I didn’t realize even in my dreams that it would cause such a big uproar. I thought of turning myself in to police but I couldn’t bring myself to do it,” the letter, which bore a Nagoya postmark, said.

Santen announced June 15 that it had received a blackmail letter that threatened to mix caustic soda into its eyewash products and the company had started recalling all its 24 types of nonprescription eyewash.

The blackmailer , who enclosed in the letter a bottle of eyewash mixed with gasoline, said he had a “grudge” with the pharmaceutical industry.

Police said they found the suspect had no personal ties with Santen and they suspect the reference to a grudge with the drug industry was merely a ruse.

Police said Maeda had been in the construction business and used to put a company plate, Maeda Kogyo (Maeda Industries), outside his home and was recently bothered by a back pain.

Maeda’s arrest was traced to a piece of incriminating paper he allegedly left at a copying machine in a convenience store nearby his home.

After Santen received the letter, police found a copy of what is believed to be a draft of it at a convenience store. in Moriguchi, Osaka Prefecture, about 1 km away from his home in Kadoma.

Investigators believe Maeda photocopied the draft and left a copy there June 13. The letter arrived at Santen the following day.

A security video at the store showed a middle-aged man making copies around the time the copy was believed to have been left.

The blackmailer asked the company to send an employee in a white shirt, a red tie and a baseball cap and take the cash to the roof of a department store in Osaka’s Kita Ward, setting the pickup time at 3 p.m. on June 15.

Police sources said nobody turned up to receive the money.