New York State Attorney General Eliot Spitzer said on Sunday that an investigation of the drug wholesaling business centers on possible drug tampering and mislabeling.

Appearing on ABC-TV’s “This Week with George Stephanopoulos,” Spitzer said investigators were looking at “pricing and the integrity of the drugs, whether or not there are drugs that are being adulterated, that are being tampered with.”

Spitzer attributed potential problems to “porous holes” in the chain of drug distribution.

The comments came days after the three leading drug wholesalers - McKesson Corp., Cardinal Health Inc. and AmerisourceBergen Corp. - disclosed they had been subpoenaed in a probe of wholesalers’ use of secondary sources of drugs for resale.

The three drug wholesalers, whose market share totals about 90 percent, have said the probe apparently relates to the practice of buying products from other drug wholesalers - a practice known as the alternate source market - instead of directly from the drugmakers.

Spitzer was asked by Stephanopoulos if he had reason to believe there were “fake” or “diluted” drugs on the market.

“There certainly are some. The question is what magnitude,” Spitzer replied.

Analysts have said the investigation is expected to have a minimal impact on the industry.