Over the past decade, companies doing business in Colombia, like Chiquita Brands and Dole Food, have incurred the wrath of Terrence Collingsworth, a lawyer who has accused them of mistreating workers or conspiring to kill labor activists.

But these days, Mr. Collingsworth is on the defensive. One of his targets, Drummond, a coal producer based in Birmingham, Ala., recently asked a federal judge to hold the lawyer in contempt as part of a libel suit it is pressing against him. Chiquita and Dole, pointing to the Drummond case, have also raised questions about his practices.

The problems engulfing Mr. Collingsworth underscore the mounting difficulties facing a small group of plaintiffs’ lawyers who have carved out a niche suing multinational corporations on charges that they violated human rights overseas.

The biggest setback for this kind of litigation came two years ago when the Supreme Court sharply limited the use of an obscure law adopted in 1789, the Alien Tort Statute, to bring international claims in American courts. Meanwhile, a number of controversies involving Mr. Collingsworth and other lawyers have cast a shadow over the field and made it possible for companies to mount counterattacks.