It is estimated by Barclays that about 95 per cent of Greece's debts are held by banks operating in the eurozone.
Speaking to the Financial Times, one unnamed strategist at a UK-based hedge fund said that several firms had successfully engaged in the practice as banks look to limit their risk.
"There are a group of funds, perhaps three or four, that have played this as a huge sovereign basis trade and made a lot," it was said.
Last weekend, it was reported that private banks in Germany may start buying Greek debt, backed by guarantees from the country's government on such investments.
Last week, Fitch Ratings downgraded the credit rating of four top Greek banks, including National Bank of Greece and EFG Eurobank, in response to the economic problems afflicting the country.
By Gary Cooper