Chelsea and Abramovich, the end of an era 5:28 (CNN) — 23-time Grand Slam champion Serena Williams and seven-time Formula One world champion Lewis Hamilton have joined Martin Broughton’s bid to buy Premier League club Chelsea, a source close to the deal told CNN on Thursday. The source spoke on condition of anonymity. While he would not confirm how much either was investing as part of the consortium, he did state that they were both investing as investors in sports businesses. Roman Abramovich relinquishes control of Chelsea 0:35 The source added that former Liverpool chairman Martin Broughton’s consortium includes world athletics president Sebastian Coe, as well as Josh Harris and David Blitzer, owners of sports teams, including the Philadelphia 76ers of the National Basketball Association (NBA). A second source also confirmed Coe’s involvement in the Broughton offer. Freud Communications, Hamilton’s communications consultancy, confirmed the Formula One driver’s involvement in Broughton’s bid to CNN. Representatives for Serena Williams were not immediately available for comment when contacted by CNN. Williams is already part of a majority women-founded group that owns Angel City FC in the National Women’s Soccer League (NWSL). Broughton’s bid is one of three remaining in the race to buy the club from current Chelsea owner Roman Abramovich.