Yuki Tsunoda hit out at his former AlphaTauri team-mate Pierre Gasly at the Miami Grand Prix during practice on Friday following an incident near the end of the session.
Tsunoda was in the process of setting a hot lap time in the practice session and was navigating the last sector of the track.
His attempts were scuppered by Gasly though as the Japanese racer felt as though he was blocked by the Alpine prior to the start/finish straight.
Tsunoda, who has gained a popular reputation with fans for his frank and sometimes foul-mouthed team radio messages, was angry with Gasly.
He shouted down his team radio: “What the f*** is he doing, honestly? This idiot."
Tsunoda loses cool once again
It is not the first time Tsunoda has been heard shouting obscenities down the team radio with the Japanese driver almost becoming synonymous with angry exchanges.
He has previously been warned about his conduct by AlphaTauri boss Franz Tost and Tsunoda accepts it is something he needs to work on, adding he is a 'shouty guy'.
His latest target was his former team-mate Gasly, who left AlphaTauri to join Alpine at the end of last season, forming an all-French partnership with Esteban Ocon.
Ex team-mate or not, Tsunoda was not shy in voicing his opinion on the matter over the team radio.
On Sunday, Tsunoda finished the race just outside the points in 11th with Gasly earning four points for eighth position.