The allegations of fraud at Afinsa, a Spanish stamp group, have put the spotlight on its main subsidiary, Escala Group, which has become the biggest global player in the sometimes murky realm of coins, stamps and collectables.

Escala was created in 2003 with the merger of two big auction houses, Greg Manning in the US and Auctentia in Spain. The group's operations were folded into Greg Manning, which was listed on Nasdaq, and the entity was renamed Escala. Since then it has expanded rapidly through further acquisitions, hired a new chief executive, shifted its head office from New Jersey to New York City and seen its share price rise from under $5 to $35.