The mother of a black teenager who was found dead in Epping Forest has rejected an apology from the Metropolitan Police following the “substandard level of service” she received.

Evidence Joel filed a complaint against the Met after her son, Richard Okorogheye, was found on April 5, two weeks after he went missing.

The 19-year-old, who had sickle cell anaemia, left home without his medication.

Police watchdog the Independent Office for Police Conduct (IOPC) subsequently launched an investigation which concluded last month.

On Wednesday, the IOPC said the force should apologise to his family after officers provided an “unacceptable level of service” to Ms Joel.

It added it found the performance of three police officers and three call handlers fell below the standard expected, but their actions did not meet the threshold for disciplinary action.

Deputy assistant commissioner for the Met, Bas Javid, said he “apologises for the distress caused by the substandard level of service”.

Ms Joel rejected the apology.

In a statement issued through her lawyers, she said: “The IOPC investigation has confirmed what I always knew – in the darkest period of my life, I was dismissed by multiple Metropolitan Police staff at all levels of seniority and my son’s disappearance was not taken seriously.

“It is a matter of deep regret to me that despite both the IOPC and Metropolitan Police concluding that the performance of three police officers (including an inspector) and three call handers fell short of the standard expected, nobody will face misconduct proceedings.

“Therefore the apology is not accepted.”

Tara Mulcair of Birnberg Peirce solicitors, which represents Ms Joel, added: “It is regrettable that the Metropolitan Police have decided to apologise to Ms Joel now, almost 16 months after his (Mr Okorogheye) disappearance and only after a recommendation from the IOPC.”

The IOPC probe found that Mr Okorogheye should have been classed as a missing person earlier and he was defined as low risk for too long, while a call handler inaccurately recorded his medical condition as anaemia rather than sickle cell anaemia on the initial police report.

However, evidence did not show that the delay in upgrading Mr Okorogheye’s risk level was due to his or Ms Joel’s race, it added.

Ms Joel also claimed a police officer made a racist comment but the watchdog said that, while it could be considered “unprofessional”, it could not conclude the remark was “influenced by any bias regarding Richard’s ethnicity”.

IOPC regional director Sal Naseem said: “We found that call handlers did not record or pass on information as they should have done and may have given Ms Joel a false impression about how they were treating her son’s disappearance, which can only have increased her frustration and anguish.

“Allegations of discrimination which are not overt are often difficult to prove and finely balanced. The evidence shows Ms Joel did have good reason to believe her concerns were not being taken seriously.

“She made multiple phone calls to police and concerns she raised about his condition were initially either mis-recorded or underestimated.

“While officers are not expected to have a specific level of medical knowledge, it does make it vital that concerns raised by family members or medical professionals are given proper consideration, which did not happen in Richard’s case.”

Deputy assistant commissioner Javid said: “It is clear the service we provided in the days following Richard’s disappearance was not at a level the public would expect of us … we will address these issues directly with the officers and staff involved through additional enhanced training.

“We recognise how worrying it must be to not know where a loved one is, and we are challenging ourselves to do better at responding when someone does report a missing person.

“To help us improve we are working with partners, such as the charity Missing People, to understand and learn from the experiences of different communities across London.

“We are also introducing a new way to assess all the missing person reports we receive every day.”