LONDON — First centered on Britain and Ireland, the scandal over beef products adulterated with horse meat escalated across Continental Europe on Tuesday after Nestlé, one of the world’s best-known food companies, said it was removing pasta meals from store shelves in Italy and Spain.

Nestlé, which is based in Switzerland, said it had increased testing after the discoveries of horse meat in British foods and “traces” of horse DNA in two products made with beef supplied by a German company, H. J. Schypke.

The involvement of Nestlé is a significant act in a fast-moving situation that is forcing Europeans to question the contents of their meals.

Before the announcement, the horse meat crisis had already spread, with perhaps a dozen countries caught up in product recalls.