The Internal Revenue Service is seeking information from an additional 70 companies including airlines, car dealerships and retailers in its continuing probe of people who use offshore credit cards to evade US taxes.

The IRS filed petitions in federal district courts around the country to obtain the business records.

The IRS said it has received "significant information" from MasterCard International concerning cards issued by banks in more than 30 countries, including Switzerland and Caribbean nations such as Bermuda and the Cayman Islands.

However, the IRS said in order to identify many people using the offshore cards, it needs additional information from merchants.

The IRS has already received permission in recent weeks to seek information from 40 companies, including major airlines and hotel chains, but the agency said none of the firms or merchants are under investigation.

Separately, the IRS warned against tax avoidance schemes that rely on reinsurance companies to create improper tax breaks for car dealers, retailers and other businesses.