Swiss bankers say that foreign countries must not abuse judicial assistance from Switzerland for political purposes.
And they are pressing the Swiss authorities not to "close their eyes" to possible injustices in a foreign prosecution.
"Suspect, or at least doubtful, requests should be refused or additional information sought, regardless of fears that this might cause diplomatic friction," argued Urs Roth, chief executive of the Swiss Bankers Association at a news conference in Zurich on Wednesday.
The issue has been raised because of the Swiss authorities' role in blocking bank accounts and freezing assets, in particular those linked to Russia's Yukos oil company.
"We have seen various procedures in the past few years when the authorities in foreign states, and that includes not only in Russia but also other countries, asked for legal assistance. In some cases it was doubtful whether it was a criminal procedure or rather a political procedure," Roth told swissinfo.
He said his association wanted Swiss judicial authorities to concentrate more on checking the details submitted by foreign authorities to see whether they warranted judicial assistance.
He did not attack any individual or federal authority, although the office of Swiss Federal Prosecutor Valentin Roschacher came under fire last year for its handling of the Yukos affair.
"We on purpose brought this subject to the table today when there is no actual procedure going on, so as not to be seen to be criticising any particular staff of any particular [Swiss] authority.
"[Our aim] is to help foster a discussion about the substance and that is really what matters in this case," he added.
Roth told the news conference that there were suspicions that judicial authorities abroad sometimes started a prosecution procedure as a pretext to gain access to financial information.
"Switzerland must not be pushed by the judicial-assistance process into becoming a simple purveyor of information," he warned.
In an apparent indirect criticism of the Swiss authorities, he said they "systematically assumed" that a requesting state was proceeding in accordance with the same legal norms as applied in Switzerland.
"There must be no jeopardising of either the protection of individual rights, which is a highly valued principle in Switzerland, or of the trust foreign customers and investors have in our legal system," he added.
He also warned that although Switzerland should not interfere with legal proceedings abroad, it had a responsibility to see that the legitimate defence rights of an accused person were guaranteed under the judicial assistance procedure.
Roth said that legal experts and practitioners had been "increasingly critical" of the judicial assistance practice of Swiss authorities.
"We think these experts and practitioners are absolutely right... we as banks regularly need to block accounts, freeze in some instances large amounts of money which are then not at the disposal of enterprises which are affected by these investigations. [This money] might be very critical for these enterprises to survive," he said.
"Judicial assistance cannot be allowed to serve domestic political goals by being misused to exert pressure on influential or politically unpopular persons or companies," he added.
Roth said that Swiss authorities at both the federal and cantonal levels had to look at the facts and not formal demands.
swissinfo, Robert Brookes in Zurich
The Swiss Bankers Association was founded in Basel in 1912 and today has a membership of roughly 370 banks and about 9,200 individual members.
Its secretariat employs a staff of more than 50.
Key industry issues are dealt with in 15 commissions. The 180 commission members are drawn from all banking groups and are joined in their work by specialists from the association.
On the eve of Swiss Bankers' Day, the Swiss Bankers Association gave the following assessment of the Swiss economy:
It said the economy was likely to grow less this year than in 2004.
The association reported the banking sector recorded a "welcome increase" in earnings last year to reach SFr58.5 billion ($46.5 billion), up by 6.4 per cent compared with 2003.
In 2004, the balance sheet total for all banks in Switzerland was SFr2,490 billion or 11 per cent higher than in the previous year.