Drug mules are going to dangerous new lengths to smuggle illegal substances into Britain, swallowing up to 110 packages of heroin and cocaine before passing through customs. The UK Border Force said the so-called "swallowers" can make around £1,000 per trip but face serious illness or even death should one of the packages burst.

The drugs are typically carried inside balloons, condoms or cling film, with the mules using dangerous levels of diarrhoea medication to prevent them needing to use the toilet during their journey. Many will also starve themselves for days on end before travelling in the UK.

The UK Border Force cited one example where a drugs mule went for three weeks without going to the toilet, surviving on only a sip of water and the skin of an apple a day. While many of the smugglers enter the UK via its airports, others have been caught using the Eurostar train.

In one case cited by the Home Office, Jaroslaw Adamski was jailed for four years after pleading guilty to carrying a kilogram of heroin inside his body. The 51-year-old, who was caught upon arrival at London St Pancras station in February 2015, told Border Force officers that he had been approached by a man in his native Poland and was paid €15 (£11) for every package he swallowed.

Andy Coram, assistant director of Border Force South East & Europe, said: "These cases show the lengths smugglers will go to in their attempts to bring Class A drugs into the UK." He added: "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."

Immigration minister James Brokenshire said: "Security is our priority and our officers are not there to just stamp passports; they play a vital role in stopping this type of cross-border crime and preventing dangerous drugs entering the UK which blight communities."

In the last year, the UK Border Force has seized nearly 9,000lbs of Class A drugs, according to The Independent. The vast majority of these substances have been smuggled in from abroad.