MARTIN HANSSON, the referee in charge of Liverpool's recent Champions League clash with Atletico Madrid, has admitted receiving death threats over his decision to award a late penalty to Liverpool captain Steven Gerrard.

The Swedish referee pointed to the spot in the fourth minute of stoppage time of the game at Anfield, which Atletico were winning 1-0 at the time, for what he perceived to be a push on Gerrard from Mariano Pernia. The decision has since been derided by many at Atletico and in the Spanish media.

Hansson told Swedish newspaper Sport-Expressen he has had to change numbers and inform the police over a number of threatening calls and text messages. "I have received death threats. It has been horrible and feels very uncomfortable," he said.

Hansson insists he will not quit the game, as his compatriot Anders Frisk did after receiving threats following a game between Chelsea and Barcelona in 2005.

Former Brazil striker Ronaldo has revealed he could choose to retire rather than prolong his career after fighting back from a knee injury. The 32-year-old spent nine months on the sidelines after rupturing a tendon in his left knee while playing for AC Milan in February but returned to action earlier this week, playing 22 minutes of an exhibition match.

Ronaldo's contract with Milan expired in the summer and he has been training with Brazilian side Flamengo. "I don't know if I will continue to play or if I will retire," he told La Gazzetta dello Sport. "I have not taken a decision yet."