SAN FRANCISCO: A firm specializing in transferring cryptocurrency said that hackers have sent back a portion of the digital loot from a record haul.

Poly Network fired off a tweet early Wednesday saying it had received about $4.8 million worth of the stolen assets back, hoping for more from the online heist potentially valued at more than $600 million.

Later in day, digital asset research firm The Block put out word that $256 million worth of swiped “tokens” had apparently been returned.

“They have now sent back $256 million in tokens out of the haul,” The Block said in a post at its website.

“Seven minutes prior to sending the first transaction returning some of the funds, the hacker created a token called ‘The hacker is ready to surrender’ and sent this token to the designated Polygon address.”

Polygon had urged the hackers to return the stolen fortune and provided online addresses for transfers.

One of the touted features of cryptocurrency is that blockchain transactions are public, even if the people behind them are not.

Poly Network had put out a plea for the stolen Ethereum, BinanceChain and OxPolygon tokens to be shunned by traders running “wallets” for storing cryptocurrency.

“The amount of money you hacked is the biggest one in the defi history,” Poly Network said in a tweeted message to the thieves, using a reference to decentralized finance involving cryptocurrency. “The money you stole are from tens of thousands of crypto community members.”

The return of some of the digital loot came as the thieves were tracked by “white hat hackers” who use their software skills for good.

The heist also sparked debate about whether it would be fair to let the hackers keep some of the loot as reward for uncovering a Poly Network weakness that could have been even more costly.

Open source developers alliance BinomialPool in a tweeted exchange proposed a bounty of 5 percent to 10 percent for pulling off such crypto-hacks.