Saudi Arabia's central bank has ordered local banks to freeze the accounts of a Saudi billionaire, a source was quoted as saying.

The Saudi Arabian Monetary Agency (Sama) also ordered banks in the country to freeze transactions with Maan Al Sanea, the chairman of the privately-held Saudi conglomerate Saad Group and owner of a three per cent stake in HSBC Holdings, according to a report in our sister newspaper Gulf Daily News.

Sama did not provide any explanation for the order, which was sent to banks in the kingdom on May 28, and also affects five of Al Sanea's relatives, including his wife and children. It includes their accounts and credit cards, Sama's order asks 'for everything to be frozen, including credit cards,' the source said.

Forbes magazine lists Al Sanea as the world's 62nd richest man, with a value of about $7 billion.

A spokesman for HSBC's affiliate in Riyadh declined to comment on the move, which was first reported yesterday in a Saudi newspaper.

The newspaper, citing unidentified high-level banking sources, said Al Sanea's accounts had been frozen, and linked the move to the recent debt default by a bank.

The newspaper said it learned there 'was a connection between Al Sanea ... and the inability of the bank ... to meet its debts.'

It did not elaborate on the relationship, but Al Sanea is married to a member of the family, whose firm owns the bank.