"I wish to refute the claim by PETA that I am or will be a spokesperson forthat organisation," Chappell said in a statement.
PETA had issued a statement a few days back, saying Chappell recommended vegetarianism in his book titled Health and Fitness.
The former Australian captain said PETA was wrong to use his name for their "wider campaigns".
"Some years ago I gave permission to a representative of the PETA organisation to reprint a book of mine for use in Indian market to promote a healthy lifestyle.
"At no stage did I agree to become an ambassador for their wider campaigns.
"I will be contacting PETA and asking them for an apology," Chappell said in his statement.