A South Korean arrested in Japan in connection with an explosion at a controversial shrine in Tokyo last month had no gunpowder in his belongings when he left from a Seoul airport, a media report said Friday, quoting airport authorities.

The revelation came after Japanese investigative sources claimed that what appeared to be gunpowder had been found in the baggage of the suspect, Jeon Chang-han, 27, when he came back to Japan on Wednesday.

Yonhap news agency said a security officer at Gimpo International Airport noticed a bag of black powder that Jeon had. The substance was screened through an explosive detection device, but no gunpowder ingredients were spotted.

However, since the detailed nature of the substance was unknown, he was asked not to pack it in his carry-on baggage, the report said, and he put it in with his checked luggage for the flight.

"We have judged that it was not an explosive after close inspection and we let him depart," Korea Airports Corp. told Yonhap. "We have followed our regulations and procedures."

Jeon, whose name has been transliterated as Chon in some media reports, was arrested on his arrival in Japan on a charge of entering the premises of Yasukuni Shrine with unlawful intent. Tokyo police suspect he set explosives in a men's restroom at the shrine on Nov. 23 and was planning to carry out another blast there. No one was injured in the incident.

The sources said Jeon has denied involvement in the blast at the shrine, which is viewed as a symbol of Japan's militarist past because it enshrines war criminals along with the war dead.

Jeon emerged as a possible suspect after being caught on surveillance camera footage both before and after the blast at the shrine restroom.