Japan's Hiroto Inoue was accused of pushing by Bahrain's Elhassan Elabbassi in a controversial sprint finish to the Asian Games marathon on Saturday.
The runner-up Elabbassi lodged a complaint with race officials.
According to AFP, Inoue and Elabbassi entered the stadium in Jakarta neck and neck, before the Japanese athlete opened up a small lead.
In the final 100 metres, Elabbassi attempted to overtake Inoue on the inside but fell back after apparent contact.
"The number one (leader) pushed me," said Elabbassi.
"I would have won."
Elabbassi's coach Gregory Kilonzo said the team manager had filed a complaint over the incident. Bahrain team officials confirmed they were meeting with the technical delegate after the race.
"He was almost overtaking the number one, then the guy pushed him," said Kilonzo.
"He was pushed and almost went down. The Japan guy, when he saw he was almost overtaken, he decided to push."
Both athletes finished with a time of 2 hours, 17 minutes and 22 seconds, but pre-race favourite Inoue came in fractionally ahead.
"I don't know what happened before the end," said Inoue.
"I was surprised but I do not understand what happened."
OCA confirms Korea complaint against Chinese swimmer
The Olympic Council of Asia (OCA) has received a complaint from South Korea against a Chinese athlete for kicking swimmer Kim Hye-jin during training at the Asian Games, the governing body said on Saturday.
The Korean Olympic and Sport Committee (KSOC) said Kim had accidentally hit the female Chinese swimmer while they were training in the pool on Thursday.
The Chinese swimmer could not understand Kim’s apology and later kicked her at the Gelora Bung Karno Aquatic Center, the KSOC said, prompting coaches from both sides to step in and separate them.
OCA international director Vinod Tiwari declined to dwell on the incident in Friday's news conference but a spokesman confirmed receiving the complaint without elaborating on the procedure.
The Chinese officials apologised at the scene and later at the athletes village but the KSOC decided to lodge a complaint against the swimmer.
"Assaults should not happen in sports," Korean chef de mission Kim Seong-jo told reporters on Friday.
"Even if there was an apology from the Chinese athlete, this incident should be investigated and proper actions should be made."