Two Bureau of Meteorology employees are being investigated by the Australian Federal Police (AFP) for allegedly running an elaborate operation involving the use of the bureau's powerful computers to "mine" cryptocurrencies, ABC News has learned.

Federal police officers executed a search warrant at the bureau's Collins Street headquarters in Melbourne on Wednesday last week (February 28). The officers spoke to two IT employees, according to people with knowledge of the raid.

The rest of the bureau's IT team was ushered into a conference room and told to wait while the employees were questioned, the people said.

At least one of the employees who was questioned by the AFP has since gone on leave. No charges have been laid but the investigation is continuing.

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Cryptocurrencies, of which Bitcoin is the most well-known, are created by computers that have been tasked to solve complicated mathematical formulas in a process known as "mining". Over time, the equations become more difficult to solve, requiring miners to harness more computational power.

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Last month, a group of scientists at a Russian nuclear warhead research centre were arrested for allegedly using the facility's supercomputer to mine cryptocurrencies.

The value of Bitcoin has been on a wild ride in recent months after peaking at a high of $US19,783 per unit in December. At the time of writing, one bitcoin is worth $US10,800. The opportunity to make big profits in cryptocurrencies has sparked a flurry of speculative interest.

While mining cryptocurrency is not illegal, use of the bureau's computers to carry out the process could be an illegal use of government resources.

A spokesperson for the bureau declined to answer questions, citing the ongoing investigation, as did the AFP.

If the employees were mining cryptocurrency, they may have been using the bureau's computers to either avoid the significant electricity bills involved in mining, or they may have been taking advantage of the bureau's powerful computational power, said Chris Berg from RMIT's Blockchain Innovation Hub.

"One possibility is that they're trying to use some of the equipment that the Bureau of Meteorology have. The Bureau of Meteorology has some very fast computers. Another possibility, though, is that they're just trying to get the Bureau of Meteorology to pay for the electricity. Mining is a very electricity-intensive task and they probably didn't want to pay for it themselves," said Dr Berg.

Bitcoin was created a decade ago and was followed by a series of other digital currencies such as Ethereum and Ripple. Most rely on a principle known as the blockchain, essentially a digital ledger that records transactions in a permanent, verifiable way.

"If you mine cryptocurrency you're rewarded for doing so in the cryptocurrency that you're mining. So for instance if you successfully mine Bitcoin... you're going to get 12.5 bitcoins, which is around $170,000," Dr Berg said.

BOM says it was "unacceptable" that the scam ads were allowed on its site.

Last month the Bureau of Meteorology made headlines when it apologised for hosting fake advertisements directing people to a Bitcoin scam, though that scam is not believed to be connected to the current investigation.