British world championships medallist Bianca Williams, 29, and Portugal Olympic sprinter Ricardo Dos Santos, 28, say they were racially profiled.
They were handcuffed and searched outside their West London home while their baby was in the car in July 2020.
Ms Williams filmed it, and their coach, Linford Christie, posted it online.
During the incident, the couple were pulled over by officers in Maida Vale as they returned from a training session and searched on suspicion of having drugs and weapons, but nothing was found.
Five Met officers were accused of gross misconduct, which they denied.
A disciplinary hearing found that PC Jonathan Clapham and PC Sam Franks lied about smelling cannabis in Mr. Dos Santos’ car and so had breached professional standards of police behavior in relation to honesty and integrity.
The panel said it was likely the smell had emanated from another area.
The hearing was told those officers were “not seen to attempt to verify the smell”, which led to them becoming “trapped in a lie” when they gave evidence.
Panel chairwoman Chiew Yin Jones said their behavior amounted to gross misconduct.