A canoeist who has been banned after admitting that he doped a fellow competitor’s drink, contrived a variety of schemes to rattle his rival, an official source said Thursday.

Yasuhiro Suzuki, a 32-year-old athlete who has already admitted secretly adding a banned substance to a drink consumed by 25-year-old rival Seiji Komatsu last September, also took his rival’s passport and cash, and defamed him in emails. Suzuki has already apologized to Komatsu in writing.

Suzuki has been banned from competition by the Japan Anti-Doping Agency, while the Japan Canoe Federation has said it would seek a permanent ban.

According to an official, Suzuki, without any Olympic experience, last year had been unable to beat Komatsu, whose star was on the rise. Suzuki had already been excluded from a spot he had hoped to earn on the four-man kayak team. With concern over his ability to earn a spot at the Tokyo 2020 Olympics, Suzuki allegedly hatched a scheme to begin harassing his rival.

At a training camp last June in Ishikawa Prefecture, Suzuki, attempting to annoy Komatsu, took his passport and ¥20,000 ($179) from the changing room. Thinking that if Komatsu were caught doping, he himself would have a chance to qualify for 2020, Suzuki’s campaign allegedly escalated at September’s national sprint canoe championships.

During qualifying, Suzuki put the steroid methandienone in Komatsu’s drink bottle. After the final, Suzuki took Komatsu’s speed meter and paddle, throwing the speed meter in a garbage can and hiding the paddle.

The loss of his passport prevented Komatsu from leaving on time for an overseas trip in July.

In September and October, Suzuki four times allegedly sent damaging emails of a private nature to Komatsu’s club.

A provisional ban on Komatsu stemming from his positive drug test has been lifted, but his records from the national meet, where he placed first in kayak sprint, have been nullified.

Earlier Thursday, canoe association President Shoken Narita briefed the Sports Agency and apologized over the drink-spiking scandal.

The Sports Agency hopes to come to grips with the incident and prevent such acts from recurring in canoeing and other sports.

“It’s very regrettable that such a thing occurred to damage how people view sports at a time when sports are a focus of attention,” Sports Agency Deputy Commissioner Yuzuru Imasato said.

The federation said it is putting in place a counseling system for athletes to help them cope with the psychological pressures of high-level competition.

“We want to quickly make a system that allows athletes giving their all under stress and great pressure to voice their troubles to someone in confidence,” said the federation’s managing director, Toshihiko Furuya.

A specialist counselor will attend the national team training camp next week.

The Ishikawa Prefectural Police are conducting an investigation in response to a report filed by Komatsu over the drink-spiking and theft of equipment.