In January 2016, Osamor was accused of hypocrisy for advertising an unpaid internship which paid expenses only. Osamor subsequently withdrew the advert, claiming it had been a "misunderstanding".
After her re-election at the 2017 general election, she was accused of plagiarising sections of her victory address from Barack Obama's 2008 speech. According to Osamor, she "deliberately invoked a victory speech so famous that she thought it needed no introduction".
This month it was revealed that Osamor continued to employ her son, Ishmael, in her Parliamentary office despite his drug-related convictions. Labour initially claimed that Osamor, who also lives with her son, knew nothing about his case until sentencing on the 26th October. However, it later emerged that she had written to the trial judge asking for leniency before his sentencing on the 19th October. She faced further criticism when it was revealed that she used parliamentary stationery and referenced her shadow cabinet position in writing to the judge.
Upon being doorstepped by reporter from The Times about the issue, Osamor threw a bucket of water, shouted profanities, and said "I should have come down here with a...bat and smashed your face open". Osamor was first referred to the Parliamentary Commissioner for Standards in November 2018, by a Conservative MP, and the investigation was expanded following the incident with the journalist. She denied any wrongdoing, and called the initial referral "politically motivated".
Osamor resigned from the Shadow Cabinet on the 1st December 2018, stating she needed "to concentrate on supporting my family through the difficult time we have been experiencing". She later tweeted that she was "deeply sorry for (her) emotional outbursts and ... working to better manage (her) feelings".
On the 19th March 2020, the Standards Commissioner found Osamor guilty of two breaches of Parliamentary rules. The first breach was the use of House of Commons paper for her son's reference, and the second was the abusing and assaulting the journalist. She was ordered to produce a written apology for her actions. Osamor accepted that she broke the rules and apologised to the Commissioner, although she later commented that she was "the target of a witch-hunt, and that race and class were factors".