Luis Suarez has been banned for 10 matches for biting Chelsea's Branislav Ivanovic, the English FA has announced.
The sanction was imposed on Wednesday by an independent regulatory commission on a charge of violent conduct against the Liverpool striker.
An FA statement said: "A three-person independent regulatory commission today upheld the FA's claim that a suspension of three matches was clearly insufficient and the player will serve a further seven first-team matches in addition to the standard three.
The suspension begins with immediate effect."
Suarez has until midday on Friday to appeal the additional suspension.
"Liverpool are going to have to make a decision re Suarez and the future" - Mark Lawrenson
In a statement, Liverpool's managing director Ian Ayre said the club was "shocked and disappointed" by the suspension.
"Both the club and player are shocked and disappointed at the severity of today's Independent Regulatory Commission decision," said managing director Ian Ayre.
"We await the written reasons before making any further comment."
Ian Ayre:"Both the club & player are shocked & disappointed at the severity oftoday's Independent Regulatory Commission decision." #LFC— Liverpool FC(@LFC) April 24, 2013
Former Liverpool defender Mark Lawrenson believes the latest ban leaves the club in a difficult position.
Lawrenson told BBC Radio Five Live: "The thing about Suarez is he is now becoming a constant offender, and Liverpool are going to have to make a decision re Suarez and the future.
"I think it's a possibility he will have to leave. They are trying to sell season tickets at the moment and people will be saying 'hold on a minute, is Suarez going be here, is he going to miss 20% of the season?' It's a really tough one for Liverpool."
The 10-game ban is harsher than the eight-match suspension handed to Suarez in December 2011 for racially abusing Manchester United's Patrice Evra, and significantly more than the four-game ban given to Chelsea captain John Terry last year for racist abuse.
QPR midfielder Joey Barton was given a 12-game ban last season, for a red card and violent conduct towards three players.
In 2006, the FA banned Manchester City's Ben Thatcher for eight matches for an elbow incident that left Portsmouth's Pedro Mendes unconscious.
A 10-match ban will see Suarez miss Liverpool's remaining four games of this season and the first six domestic matches of the next campaign, potentially ruling the Uruguayan striker out until October.
Suarez had pleaded guilty to the charge of violent conduct but had denied the FA's claim that the standard punishment of three matches was "clearly insufficient" for the offence.
The three-person regulatory commission included a former player and dealt with the case under the FA's fast-track system.
It also appears that Suarez's past has counted against him - the 26-year-old was banned for seven matches in Holland in 2010 when he sank his teeth into Otman Bakkal, and although that incident did not form any part of the FA's case as it was in a different country, the commission had the discretion to take his personal disciplinary history into consideration.
The same approach was also taken in relation to deciding whether his eight-match racism ban should have any impact on the sanction for this case.
There is no standard minimum or maximum punishment for biting in football's disciplinary code, unlike rugby union which has a 12-week recommended suspension for first offences up to a four-year ban for the most serious biting offences.
Suarez had apologised on Monday to Ivanovic, who suffered a bruised arm from the bite, and the Chelsea defender acknowledged the apology.
Liverpool moved quickly to deal with the latest crisis surrounding their star striker and imposed a club fine which is being donated to the Hillsborough families' support group.
Suarez will remain eligible for the Professional Footballers' Association Player of the Year award, for which he has been shortlisted, with the announcement on Sunday.