UPDATE (14th April 21:50 BST): This article has been updated to reflect that the ETC refund effort has been extended to January 2018.

More than $4m worth of classic ether remains in a DAO refund smart contract that has been extended to next January.

Some background: last summer, a project called The DAO raised more than a hundred million dollars worth of ether – the cryptocurrency underlying the ethereum network – as part of a bid to create a smart contract-based funding vehicle for ethereum-related projects.

Yet a flaw in the code was exploited, allowing an attacker to effectively walk away with tens of millions worth of ether – effectively scuttling the project in the process. It also sparked an effort to secure some of those funds on behalf of DAO investors, a process that wasn’t without controversy.

Ultimately, the drive to unwind the effects of the DAO collapse resulted in two distinct ethereum-derived blockchains: ethereum and ethereum classic. In the end, contracts were set up allowing users to exchange their DAO tokens for both ether and classic ether.

Community members have been pushing for users to withdraw their funds, but as noted above, just over 1.5m classic ethers – worth just over $4m at press time – haven’t been accessed.

Yet a plan to transfer the remaining funds to the group that originally secured them has drawn its share of critics.

Some have taken to social media to argue that the money represents stolen property that should be returned to their respective owners, or should at least be left untouched within a defunct smart contract.

Notably, the other major DAO-related withdrawal contract, for the exchange of DAO tokens for ETH, contains more than 450k unclaimed ethers, worth roughly $21m at current prices.

Clock image via Shutterstock