Drug smuggling arrests and seizures are up in Peru ahead of the Olympic Games in neighboring Brazil, with foreigners carrying packs of cocaine in their stomachs risking death to cash in on a potential spike in demand, police said on Tuesday.

At least 98 so-called drug mules, mostly foreign citizens, have been arrested at the airport in the capital Lima since January, an increase from previous periods, said Luis Pantoja, the chief of Peru's anti-narcotics police department.

Authorities have also confiscated 19.6 tonnes of narcotics, the vast majority of it cocaine and cocaine paste, so far this year, up 25 percent from the same period in 2015, Pantoja said.

"If we keep that up through December, we'll have beaten the historic record in drug seizures," Pantoja said. He said police had also seized record levels of precursor chemicals used to make cocaine.

Pantoja said it was unclear what was driving the trend, but said throngs of visitors headed to the Olympic Games might be bolstering demand in Brazil, the second biggest consumer of cocaine in the world after the United States.

Authorities in Peru reported a spike in drug-trafficking before Brazil hosted the World Cup in 2014. Peru is virtually tied with Colombia as the world's top cocaine producer.

Pantoja said a Nigerian man died late last year when the latex packets of cocaine he had swallowed to smuggle the drug across Peru's border with Brazil broke open in his stomach.

"There's a history of people dying this way," Pantoja said.

A law went into effect in Peru earlier this year allowing the military to shoot down aircraft suspected of carrying drugs - prompting traffickers to turn to boats and backpackers to move their cocaine out of a remote jungle region.

Brazilian authorities have been tightening border controls ahead of the start of the Olympic Games on Friday.