A federal prosecutor in Washington has contacted The New England Journal of Medicine, considered the world’s most prestigious medical journal, with questions that suggested without evidence that it was biased against certain views and influenced by external pressures.

At least three other journals have received similar letters from Edward Martin Jr., a Republican activist serving as interim U.S. attorney in Washington. Mr. Martin has been criticized for using his office to target opponents of the administration.

In the interview, Mr. Kennedy said he would seek to prosecute medical journals under federal anti-corruption laws.

“I’m going to litigate against you under the racketeering laws, under the general tort laws,” he said. “I’m going to find a way to sue you unless you come up with a plan right now to show how you’re going to start publishing real science.”