Major League Baseball’s investigation of an anti-aging clinic linked to performance-enhancing drugs has taken a new turn, with the commissioner’s office paying a former employee of the facility for documents related to the case. At the same time, two people briefed on the matter said, at least one player linked to the clinic has purchased documents from a former clinic employee in order to destroy them. The unusual battle, according to the two people, also appears to involve efforts by other players tied to the clinic to buy potentially incriminating documents and keep them out of the hands of baseball’s investigators. One of the two people said that, in part, baseball, which has no subpoena power, felt compelled to pay money for documents because its officials had been concerned that more than one player was trying to do the same. In addition, the two people said, baseball has now provided payments to former employees of the clinic who have cooperated with the sport’s investigators. The payments were for the time they provided to the investigators, the two people said, and, in each instance, were not believed to have exceeded several thousand dollars. That baseball is paying for evidence underscores just how determined it has become in establishing what went on at a now-closed South Florida clinic that operated under the name Biogenesis of America. The clinic is suspected of providing performance-enhancing drugs to a number of major leaguers. In January, a weekly newspaper, Miami New Times, reported that it had obtained medical records from the clinic that tied half a dozen players — Alex Rodriguez, Melky Cabrera, Gio Gonzalez, Bartolo Colon, Nelson Cruz and Yasmani Grandal — to the use of banned substances like human growth hormone. More records then emerged that tied other players, including Ryan Braun, to the clinic. In turn, many of the named players, including Rodriguez and Braun, denied obtaining any banned substances from the clinic. But the denials have essentially been brushed aside by baseball and its investigators, who remain intent on obtaining whatever testimony and evidence they can in connection with the clinic’s activities and determining whether they then have grounds to discipline players even in the absence of a positive drug test. Indicative of Major League Baseball’s resolve in this case, Commissioner Bud Selig sent two of his top deputies — Rob Manfred and Pat Courtney — to Florida in February to try to persuade Miami New Times to share the documents it had obtained. The newspaper declined. Then, last month, baseball filed a lawsuit against six people with connections to the Biogenesis clinic, accusing them of damaging the sport by providing players with banned substances. At least in part, the suit appears designed to give baseball the ability to subpoena records from the clinic and compel depositions. But baseball has now gone a step further in paying to obtain evidence.