FTX US general counsel Ryne Miller said in a tweet today that the exchange was expediting the process of shifting all digital assets into cold storage “to mitigate damage upon observing unauthorised transactions.”

Cold storage refers to crypto wallets that are not connected to the internet to guard against hackers.

Late on Friday, Miller tweeted that he was “investigating abnormalities with wallet movements related to consolidation of FTX balances across exchanges.”

Figures from Singapore-based analytics firm Nansen showed a one-day net outflow from FTX of about US$266 million, with US$73 million withdrawn from FTX US alone.

FTX did not respond to a Reuters request for comment.

Prior to Miller’s tweets, FTX officials appeared to confirm rumours of a hack on the firm’s Telegram channel, according to a CoinDesk report which said that the exchange had instructed customers to delete FTX apps and avoid its website.

“FTX has been hacked,” an account administrator in the FTX Support Telegram channel wrote in a message, according to CoinDesk.

Reuters could not immediately verify the details posted on FTX’s private Telegram channel.

FTX, affiliated crypto trading firm Alameda Research and about 130 of its other companies have filed for bankruptcy court protection from creditors in Delaware, FTX said on Friday.

The distressed crypto trading platform had struggled to raise billions as traders withdrew US$6 billion in crypto tokens from the platform in just 72 hours and rival exchange Binance abandoned a proposed rescue deal this week.