London - Britain's Border Force said on Tuesday that gangs were using more sophisticated swallowing packages to smuggle drugs into the country, sometimes ingesting more than 100 at a time.The majority of drugs mules attempt to pass through Britain's main airports but they have also used trains from continental Europe, the law enforcement command said.Border officials said so-called "swallowers" typically swallow between 80 and 110 packages at a time, with drugs sealed in condoms, balloons and plastic wrapping film.Polish national Jaroslaw Adamski was jailed for four years after admitting carrying nearly 1kg of heroin in his body into London's Saint Pancras international train terminal in February.The 51-year-old told Border Force officers he was paid about R251 per package swallowed. The high-purity heroin, if cut and sold, had an estimated value of about R3.5m.Sniffer dogsIn another case cited by the interior ministry, one man went for three weeks without going to the toilet, surviving on only a sip of water and the skin of an apple a day, in an attempt to stop the drugs packages passing through his system."These cases show the lengths smugglers will go to in their attempts to bring class A drugs into the UK," said Andy Coram, assistant director of Border Force South East and Europe."Those who swallow packages like this are risking their lives and we are seeing more and more sophisticated purpose-made swallower packages, which show the organisation behind this type of smuggling."Officers use tactics including X-ray screening and sniffer dogs trained to identify chemicals secreted in the skin to try to detect drugs mules.Over the last year, the Border Force has seized nearly 4 000kg of Class A drugs.