Investigative journalism depends on undercover reporting as an effective investigative method that allows journalists to reveal hidden realities and essential societal matters. The practice of undercover reporting normally causes substantial ethical problems and privacy violations. The research identifies privacy invasion limits in undercover reporting through an analysis of public interest versus personal rights protection. This study uses journalists and legal experts, as well as ethical expert interviews combined with case studies, to examine how undercover journalism affects ethical questions, legal requirements, and societal effects. This research shows that public interest stands as a common excuse for privacy intrusions, yet its meaning extends differently in different cases. The research identifies several obstacles that exist because of different legal systems between jurisdictions and the evolution of digital observation practices and consent and wiretap legislation. The analysis recommends building uniform ethical rules for journalism accompanied by training for practitioners in news ethics and legal advising, together with enhanced safeguards for journalists and continuous society-wide discussions about covert journalism standards.