Up to 20 cyclists from the Tour of Flanders, including race winner Tadej Pogacar, could face action from Belgian authorities after running a red light at a railway crossing on Sunday.
While the main peloton stopped as required, Pogacar and a bunch of chasers slipped across the tracks in pursuit of a leading group, despite the warning signals and the risk of an oncoming train.
Pogacar said he and several others were alerted to the red light too late.
"Suddenly, three guys jumped in the middle of the road and started waving to stop. How can you stop in one second," he said.
Pogacar also said he at first thought he might be dealing with some kind of protest, which is common at bike races held on public roads.
"I was thinking maybe it's some protesters or something crazy is going on."
The East Flanders public prosecutor's office announced it would pursue the riders for breaching road safety rules.
"The offenders will be identified and a report will be filed," the local prosecutor's office said.
Race organisers forced the group that went through to slow down and wait for the rest of the peloton to catch up once the train had passed, but the breakaway was allowed to keep racing and they stretched their lead by nearly two minutes in that period.
"The rule is a little bit weird. I don't know why they don't stop the breakaway, stop us and then restart normally like it should be. In the end, no complaints," said Pogacar.
Belgian hero Remco Evenepoel, who finished third on the day, was also among the riders concerned.
The offence could land them in court and incur a fine but race officials decided not to disqualify those involved in the incident.
In a separate case, Pogacar was fined 500 Swiss francs ($625) by cycling's governing body for littering outside a designated area, while Evenepoel must pay 200 Swiss francs for a "sticky bottle" episode.
That is when a rider pulls alongside a car and takes hold of a water bottle from his team, clinging to it while being towed along by the vehicle.