Scrupulous (adjective)

1. Having or showing a strict regard for what one considers to be right; having or showing a conscientious regard for honor and integrity.
2. Having or showing a strict adherence to moral principles and integrity.

Origin:

Late middle english: from latin scrupulus "a small sharp stone, a scruple" (in late latin "a cause of anxiety") + -ous. the original sense was "full of small sharp stones, causing anxiety or doubt", hence "fastidious, meticulous".

Examples:

1. She was scrupulous in her attention to detail.
2. He was scrupulous about adhering to the company's code of conduct.
3. The lawyer was scrupulous about maintaining client confidentiality.
4. The accountant was scrupulous in her handling of the financial records.
5. The researcher was scrupulous in her methodology.