The majority appear to have issues verifying their identities when trying to withdraw money from the platform. The people who BI spoke to are angry that they have received little to no communication from the platform about the issues, leaving them confused and concerned.

Bittrex on Wednesday admitted to "significant delays" in handling customer issues but claimed the issues only affect "a small percentage of our overall user base."

Las Vegas-registered Bittrex, which has daily trading volumes of around $1 billion, said the "enhanced" identification procedures were part of efforts to comply with US banking regulations and to protect users from fraud and theft. It said in a statement that it has recently hired more staff to try and tackle the issues.

The incident highlights teething problems for the fast-evolving cryptocurrency space, which has attracted billions of dollars of investor money in 2017 but remains largely unregulated and untested.