Hans-Gunnar Liljenwall is a Swedish modern pentathlete who caused the disqualification of the Swedish men's team at the 1968 Summer Olympics held in Mexico City for his alcohol use. Liljenwall was the first athlete to be disqualified at the Olympics for drug use, following the introduction of anti-doping regulations by the International Olympic Committee in 1967.

Liljenwall reportedly had "two beers" to calm his nerves before the pistol shooting portion of the modern pentathlon. The Swedish team eventually had to return their bronze medals.

At the 1972 Summer Olympics held in Munich, 14 modern pentathletes tested positive for tranquilizers before the pistol shooting event. However, although the drugs were banned by the sport's governing body, the International Modern Pentathlon Union, they were not on the IOC's list of banned substances and no disqualifications were made.

Reference

• Sveriges Olympiska Kommitté - Mexico City 1968