Biting controversies in sport
In the wake of Chelsea's FA Cup exit to Everton, questions are being asked as to whether or not striker Diego Costa bit opponent Gareth Barry.
The fiery Spain international saw red for the first time in his Chelsea career after an altercation with Barry, in which he appeared to motion to bite the midfielder. The pair actually ended in an embrace but the incident is likely to come under further scrutiny.
Chelsea boss Guus Hiddink said it was "difficult to say yes or no" as to whether Costa had bitten Barry, adding that he had not seen the incident.
Here, Press Association Sport looks at other incidents where biting has occurred in professional sport.
:: Luis Suarez (Soccer)
Barcelona striker Suarez has thrice found himself in the middle of biting incidents. Firstly, while playing for Ajax he was given a seven-game ban for sinking his teeth into PSV's Otman Bakkal. He left Holland for Liverpool but got into biting trouble there when he attacked Chelsea's Branislav Ivanovic. The Football Association gave him a 10-match ban. Finally, at the 2014 World Cup he did the same to Italy's Giorgio Chiellini, resulting in a worldwide ban of four months.
:: Mike Tyson on Evander Holyfield (Boxing)
The most notorious incident of biting in sport was when Tyson got his teeth into Holyfield and tore a chunk off his heavyweight rival's ear during their world title fight in 1997. Tyson was disqualified, but later had his boxing licence reinstated.
:: Johan Le Roux on Sean Fitzpatrick (Rugby Union)
New Zealand were heading towards a series-clinching second Test win over South Africa in 1994 when Le Roux clearly bit All Blacks hooker Fitzpatrick. Replays showed Fitzpatrick wincing in pain as Le Roux drew blood. The South African was sent home in disgrace, banned for 17 months and his international career ended.
:: Dylan Hartley on Stephen Ferris (Rugby Union)
England hooker and current captain Dylan Hartley was suspended for eight weeks for biting Ireland player Stephen Ferris during an RBS 6 Nations match in 2012. There was no television evidence, but Hartley was found guilty. A sterner penalty had been anticipated due to a 26-week ban for gouging in 2007. However, his good behaviour in the intervening period was taken into account.
:: Miguel Olivo on Alex Guerrero (Baseball)
Two team-mates on the Albuquerque Isotopes - a minor league team affiliated with the Los Angeles Dodgers - got into a confrontation during a game in 2014 , and the incident ended with one of the Dodgers' top prospects Alex Guerrero requiring plastic surgery after having a chunk of his ear bitten off by the veteran catcher Olivo. Olivo was released by the Dodgers organisation two days later.