Jumbo-Visma has been targeted by a thief at the Critérium du Dauphiné who stole a bike from the roof of a team car.
The offender took the bike, belonging to domestique Lennard Hofstede, before the start of stage three in Le-Puy-en-Velay.
Around 90 minutes before the stage start the spare bike was stacked on the roof of the team car ready for the 177km stage to Riom, when the thief removed the bike under the nose of the team mechanic.
Maassen said the mechanic moved to the second team car to pick up another bike and when he turned back the bike was gone, taken with plenty of staff and members of the public still in the area.
He added that he can remember one other occasion when a bike was stolen from the team: “In Luxembourg a while ago.
“They are striking bicycles. The perpetrator then apparently realised that he could not do much with it, then the bicycle was left somewhere in public a day later and we got it back again.”
The stolen bike would have been a team Bianchi road bike in the iconic celeste colour.
Police were called on Tuesday morning (May 11) but the thief has not yet been found.
Earlier this year, Dan Martin (UAE Team Emirates) and Romain Bardet (Ag2r La Mondiale) were targeted by thieves after they crashed in the Volta a Catalunya.
The 70km/h crash happened on a descent during the final stage around Barcelona, with big names being taken out.
To add insult to injury, Martin revealed the day after the stage that his Garmin device had been stolen from his bike while he was on the floor after the crash.
Bardet, who came off worse in the crash, also confirmed he had fallen victim to thieves.