MADRID (AFP) - Bulls will face tighter controls for steroids and other drugs at bullfights held next month as part of Madrid's San Isidro festival, daily Spanish newspaper El Mundo reported Monday, citing organisers.

Any bull that behaves in a suspect way in the ring during the festival, which will begin on May 11 and last for over a month, will undergo anti-doping testing after the bullfight, the newspaper said.

Bulls were tested at the festival before, but this time around testing will be quicker and more systematic since it will be carried out for the first time at a laboratory in Madrid, it said.

If an animal is found to have taken a banned substance, the rancher who supplied the bull can face a fine of up to 60,000 euros (95,000 dollars).

The San Isidro festival is held in Madrid's main bullring Las Ventas and it draws Spain's best matadors.

Analysis will be carried out on blood or urine samples or on samples of the animal's entrails.

The two main banned substances that are given to bulls used in bullfights are corticoid, a steroid, and tranquillizers.

Contacted by AFP, no one from the regional government of Madrid or from the city's bullfighting ring was immediately able to confirm the report.