These are early days: European, US and UK governments say the purchase of equity stakes in banks such as Citi, J.P. Morgan, Royal Bank of Scotland, Fortis and now ING, are temporary measures to get through the crisis, not a permanent extension of state control over what is a large chunk of national economies.

But it has not escaped the attention of wealth professionals that nearly all the institutions that have received state support have substantial private banking operations, in some cases operating branches in international jurisdictions such as the Channel Islands and Switzerland.

Politicians have noticed too. Last week, Vince Cable, economics spokesman for the UK Liberal Democrats, one of the opposition parties, said that the UK government should clamp down on offshore centres to ensure that banks getting state aid do not enable clients to continue avoiding paying certain taxes.

So how worried should private banks and their clients be?

“Obviously the question of confidentiality is an important backdrop to the world of private banking and wealth management generally, and clients’ views on this will not have changed as a result of the turmoil of the past few weeks,” George Kirby, management consultant at the wealth management practice of Morse, the UK-based financial consultancy, said.

“What may be true nevertheless is that the government shareholder representatives may take a position/hold a view that is more closely aligned to the 'public' interest than that of customers and or other shareholders - and it is difficult to know what that means in practice,” Mr Kirby said.

But as he continued, wealth managers should not be conniving at hiding wealth from the taxman anyway: “What is worrying is if wealth managers/private banks react sympathetically when clients feel threatened by government (and by implication/extension, fiscal authorities') presence at the boardroom table.  There is no place for tax evasion in a respectable wealth management industry; any bank that connives in/ignores this behaviour is already at risk, something the direct shareholding by government will neither advance nor slow down."

One bank that was recapitalised by the UK government was Royal Bank of Scotland, owner of Coutts, the private bank in the UK, and RBS Coutts, which operates internationally . A person familiar with the matter told WealthBriefing that a shareholder, even a government, cannot use that stake to pry into client affairs. Also, the UK government has no jurisdiction over a Swiss-regulated business, the person said.

Long before the latest events, governments had moved anyway to impose stricter reporting requirements on banks, connected to issues such as preventing money laundering and exchange of tax data. Analysts said government ownership is unlikely to produce a radical shift, particularly if such ownership is temporary.

But Sebastian Dovey, founding partner of Scorpio Partnership, a consultancy on the wealth industry and a regular commenter on its affairs, said the part-nationalisation of banks will raise some concerns.

“Clients will be re-assured in the short term by increased state intervention. Nonetheless, longer term, there may be questions asked about the performance capabilities of banks with large state ownership.”

Mr Dovey is optimistic that governments will not abuse their power and ensure the banks – and their generally lucrative wealth management businesses – make a strong profit.

“To a great extent the governments are equally motivated for the banks to succeed because of the huge sums of taxpayer money committed to the rescue. Therefore it is also in the government’s interest to make the banks perform and regain share value so that at some point in the future they can sell their equity back into the market,” Mr Dovey said..

Developments will encourage clients in a position to do so to hold more than one bank account to spread risks, he said. “Given the current state of affairs it is safe to say that most clients who did not have multiple banking relationships will do so in the future,” Mr Dovey said.

Government action may add to the trend of wealth managers at large banks choosing to go to smaller, boutique businesses, said Joan Major, director, wealth management at the UK multi-family office firm Sand Aire.

“The more entrepreneurial personnel will look to move to smaller organisations that are more independent and from our perspective, that is a good thing,” Ms Major said.

“There appears to have been a trend of clients moving from the larger banks in recent years anyway. It is possible this process leaves people feeling a bit nervous. No-one really knows how this is going to play itself out,” Mr Scott said.