The Belgian designer of a logo he charges has been plagiarised said Thursday he will take the International Olympic Committee to court over use of the design for the 2020 Tokyo games.
The IOC said last week it did not believe there was any problem with the design by Japanese artist Kenjiro Sano.
Sano rejected the plagiarism claims Wednesday as "completely baseless," saying he was "convinced this is a piece that has no parallel in the world."
Designer Olivier Debie begged to differ.
In a joint statement with his lawyer Philippe Mottard, Debie said they had decided on legal action because Sano had not demonstrated that he had arrived at the logo design on his own.
"Sano gave no explanation showing the artistic progression and development of his logo. He only explained how, according to him, the philosophy behind his design was different," he said.
"Sano's explanations do not appear to me to be convincing," he added.
Sano argued that his logo featured basic geometric features around the letter 'T' -- for Tokyo, Team and Tomorrow, with a red circle representing a beating heart.
Debie's design for a theatre in the eastern Belgian city of Liege, has a very similar shape in white against a black background but does not feature the red circle.
"The letters T and L stand out when you look at the two logos," Debie said, adding that the font used was also "strikingly" similar.
"In all, we can only state that the Tokyo 2020 logo is similar to my creation. It has been agreed that a formal legal complaint will be drawn up as soon as possible," likely by Monday.
In the first instance, Debie said the IOC will be called before a Belgian court, a process which will likely take six months.
Last week both Mottard and the Liege Theatre's lawyer wrote to the IOC and the Tokyo games organisers to halt use of the logo.
The dispute adds to the controversy surrounding the 2020 Tokyo Olympic games after Prime Minister Shinzo Abe ordered the plans for the main stadium be torn up amid growing anger over its $2 billion price tag.