Nike's multi-million dollar Olympics advertising campaign is in jeopardy.
Marion Jones, the record-breaking American athlete accused of taking performance-enhancing drugs, is in danger of being barred from the competition. She is under scrutiny by the US Anti-Doping Agency.
Jones is paid $3m (£1.64m) a year to endorse Nike (from a total endorsement budget which now stands at an obscene $1.36bn a year).
But Nike has a record of standing by athletes involved in doping scandals.