One of UBS's clients, now living in China, is being pursued by US tax authorities seeking information about his Singapore-based accounts, a report says.

The US tax authority is seeking legal authority to force UBS in Singapore to come up with a decade's-worth of financial records of a US citizen, according to the Straits Times (of Singapore).

The Internal Revenue Service has asked a federal judge in Miami to demand that the Zurich-listed bank - which settled civil and criminal charges with the US in 2009 for sheltering US accounts - divulge data on the Singapore account of Hsiaw Ching-Ye, now living in China.

UBS declined to comment when contacted by this news service.

The report said UBS was ordered to attend court in Miami on 31 March to explain why it has refused to provide the man's Singapore account records from 1 January 2001 till 31 December 2011 so the IRS can determine his correct federal tax debt from 2006 until 2011.

The report quotes UBS as saying it cannot comply with the IRS summons because "in the absence of a waiver from Mr Hsiaw, it is prohibited by Singapore's bank secrecy laws from disclosing the bank records that relate...to (his) Singapore account." The report noted that the Monetary Authority of Singapore has said previously that banking confidentiality cannot be used to shield criminal activities.

It alleged that Hsiaw had not filed a US income tax return since 2004, even though he earned income of more than $100,000 in the US from 2005 until 2007.

Court documents obtained by the publication reveal, it said, that Hsiaw had met Christos Bagios, a former banker at UBS and Credit Suisse Group who was arrested in 2012 and subsequently pleaded guilty to helping Americans cheat on taxes from 1993 to 2009. Hsiaw had met Bagios in Palo Alto, California, on 20 February 2001 to discuss his Swiss account, which was opened in 1994.

This was after Hsiaw received a warning from UBS about new tax rules that would require the bank to identify account holders having investments with US source income.

Among the documents sought are foreign bank records, including foreign brokerage or securities account records of monies deposited in the Singapore account that constitute undeclared income, as well as interest, dividends and capital gains earned in the five tax years, the report said.

Previously, the Monetary Authority of Singapore has said that it is prepared to share banking information to assist foreign criminal investigations, within established international cooperation channels for such data sharing. A country may seek from Singapore mutual legal assistance, including access to bank account information, in the investigation and prosecution of tax crimes and other serious offences.