"To compromise the investigation" means to hinder, damage, or undermine the progress and effectiveness of an official inquiry or examination into a particular matter or issue. Full definition
Contact by British Cycling with some members of staff at British Cycling prior to informing Ukad could have potentially compromised our investigation. (bbc.com)
The appellants argued that the press must have access to information on which police rely to obtain coercive court orders; the police responded that such access would compromise the investigation of serious crimes. (canadianlawyermag.com)
Rather than trying to keep the threats quiet, the airline company shared just enough information with the general public through Twitter, to help settle everybody's concerns while not compromising the investigation or people's safety. (canadianbusiness.com)