Dear [Recipient's Name], I am writing this letter to express my deep concern regarding an ongoing issue that I have been facing with a co-worker, [Co-worker's Name], at our workplace. It has come to my attention that their behavior and conduct have been greatly affecting my well-being and productivity. To provide you with context, I have been working with [Co-worker's Name] for the past [duration]. While I understand that a diverse work environment may include different working styles and personalities, I firmly believe that their actions have crossed the line and have created a hostile working environment. The main issue I would like to address is their repeated pattern of belittling and demeaning remarks targeted towards me. These derogatory comments have not only been personally offensive but have also caused damage to my professional reputation within the team. It has become increasingly challenging to perform my responsibilities effectively amidst such verbal abuse. Additionally, I have noticed numerous instances where [Co-worker's Name] has deliberately withheld important information that has directly impacted my ability to fulfill my duties. This behavior demonstrates a lack of teamwork and a blatant disregard for the success and smooth functioning of our team. Moreover, it is essential to highlight their consistent pattern of tardiness and unprofessional conduct. [Co-worker's Name] frequently arrives late to work and takes extended breaks, leading to disruptions in our shared projects and assignments. This lack of punctuality not only reflects poorly on their commitment to their role but also hinders the progress of our team as a whole. I have attempted to address these concerns directly with [Co-worker's Name] respectfully. However, any discussion regarding their actions has been met with divisiveness and a refusal to acknowledge their wrongdoings. This has left me with no choice but to bring this matter to your attention in the hopes that appropriate measures will be taken to rectify the situation. In light of the above, I kindly request that a thorough investigation be conducted regarding the behavior of [Co-worker's Name]. It is my sincere hope that an impartial assessment will be made to ensure a fair resolution. To foster a healthy and productive work environment, I would appreciate if the necessary disciplinary action is taken, which may include counseling, training, or any appropriate measure you deem suitable. I trust in your commitment to promoting a positive workplace environment where employees can work collaboratively and respectfully. Please treat this matter with the urgency it deserves, as it greatly impacts not only my well-being but also the overall productivity and morale of our team. I am willing to provide any further information or documentation required during the investigation process. Thank you for your attention and assistance in addressing this crucial matter promptly. Yours sincerely, [Your Name] [Your Employee ID/Designation] [Contact Information]