Olympic swimmer Rebecca Adlington's agent said the BBC did not take tough enough action against a comedian who joked on TV about her appearance.
Frankie Boyle told the audience of satirical gameshow Mock The Week that the 20-year-old Olympic champion resembled "someone who's looking at themselves in the back of a spoon".
The remarks provoked 75 complaints from members of the public and the BBC Trust's Editorial Standards Committee ruled they were "offensive and unacceptable for broadcast".
It also concluded the double gold medallist had not courted publicity or celebrity status, making the personal remarks unjustified.
A spokesman for Rebecca told the Daily Mail: "By giving Frankie Boyle a rebuke they fail to discourage others from doing the same in future, and that's why we have questioned the BBC Trust's actions."
A BBC Trust spokesman confirmed it had received a letter from Ms Adlington's agent.
Earlier this week, Frankie said he was unrepentant about the comments and hit back at BBC Trust's criticisms.
In an interview with Time Out magazine, he said: "The number one priority in TV comedy today is, 'Don't frighten the horses', and it's probably number two and three as well. If you look at the scheduling nowadays, it's all just celebrities meeting meerkats."