The U.S. regulator that exposed Volkswagen's rigging of emissions tests is investigating more than two dozen diesel car models made by BMW , Chrysler, General Motors, Land Rover and Mercedes-Benz to find out whether they engaged in similar cheating, the Financial Times reported.

The Environmental Protection Agency's search for software-based "defeat devices" will encompass at least 28 diesel-powered models to determine whether Volkswagen was alone in rigging emissions tests or the practice is more widespread in the industry, the FT reported, citing a document the newspaper has seen.

Reuters reported last month that the EPA and California officials would test other vehicles for possible "defeat devices" after announcing that Volkswagen uses software that turns off emissions controls in cars when driving normally and turns them on during emissions tests.

The scandal has prompted the EPA to toughen and broaden emissions tests for all automakers in an effort to thwart any other cheating activities, a move that could add to industry costs and higher regulatory hurdles.

The EPA will initially test one used vehicle of each model and then widen the probe if it uncovers anything suspicious, the newspaper said, citing a senior agency official close to the investigation.

The agency is hiring cars from rental agencies or borrowing them from owners it identifies via vehicle registration databases, the newspaper said.

The EPA is targeting most of the diesel vehicles on U.S. roads, including BMW's X3, Chrysler's Grand Cherokee, GM's Chevrolet Colorado, the Range Rover TDV6 and the Mercedes-Benz E250 BlueTec, the FT said.

Reuters could not immediately reach the EPA for comment outside regular U.S. business hours.