Two Irish Travellers were arrested in Switzerland in late March after being found to have $157,000 worth of fake cash while enroute to France.

The two, along with their Polish driver, are being held in custody under suspicion of being connected to a rhino-horn smuggling scheme.

The Evening Herald reports on the arrest of the two travellers, who hail from the Rathkeale area of Co Limerick. The two claim that their Polish driver isn’t associated with them and they found their ride only after “thumbing it,” but police believe otherwise.

The two Travellers are allegedly part of a “notorious international rhino-horn smuggling gang,” which has a huge target on its back from Europol. The gang’s senior members are all Travellers from Rathkeale.

The gang, nicknamed The Rathkeale Rovers, has established for itself a sophisticated network across Europe to facilitate their illegal trade. Through their network, the gang members are able to sell the horns illegally, and then launder and conceal the proceeds, which can typically garner over $260,000 per horn.

Rhino-horn trading is illegal as the animal is classified as an endangered species, but the black market is still active. The horn is “much sought after across the world for decoration, in the production of luxury goods and in traditional medicine, including Chinese medicine,” writes The Herald.

Last summer, the Rathkeale Rovers were believed to have played a part in a massive robbery of rhino-horns during break-ins at natural history museums in Belgium and France. Later, there was a similar but ultimately failed attempt in Brussels.

While no rhino-horns have been reported stolen within Ireland, 10 stolen horns were confiscated at Shannon Airport in 2010. The Rathkeale Rovers were allegedly connected to the illegal products.

The two Irishmen arrested in Switzerland under suspicion of smuggling rhino-horns last month remain in custody. Swiss authorities have been in contact with Irish gardai regarding the matter.