"Our police services do a hugely challenging job day in, day out, and it can be hard dealing with vulnerable people who reach crisis in a public place".
"But we can not expect the police to pick up the pieces of a broken mental health system", she said.
HM Inspector of Constabulary Zoë Billingham told the BBC that police are clearly doing a good job and definitely have a role to play, but said they are "over-stretched" and "overwhelmed" and the current system is "failing people".
Officers have also said that some mental-health services advise people with problems to call police after hours because they have nurses who can offer help and treatment.
The top five individual repeat callers to the Met all had mental health problems and called the force a combined 8,655 times past year. It cost Scotland Yard around £14,000 just to answer the calls of a single person who rang 999 more than 1,000 times in the space of a year.
"As a Force we have been vocal about changing the way people with mental health issues are treated". These crisis intervention teams very often aren't available or are simply suffering themselves from overload, so it's the police that are stuck with the problem and of course it's very demanding, very stressful for the officers.
Police are having to ignore crimes to look after vulnerable people as they "pick up the pieces" of a "broken mental health system", a damning report has found. Officers are being swamped by calls about mental illness, with the country's biggest force receiving one such call every four minutes, inspectors said.
Its analysis found that the peak time for calls to police for support with mental health-related incidents is between 3pm and 6pm Monday to Friday.
A Government spokesman said: "The NHS has worked closely with policing partners to reduce the use of police custody as a place of safety by 95% since 2011/12".
In a report on policing and mental health, which found that forces are increasingly becoming the "service of default" in response to people with mental health problems, inspectors praised South Yorkshire Police.
"Police officers do an excellent job protecting those facing mental health problems in often hard and distressing circumstances and it is right that this report acknowledges police leadership in this area to be strong".
"But we can not expect the police to pick up the pieces of a broken mental health system".
Police have been left to pick up the pieces amid a national crisis in mental health care, a watchdog report has warned. This is not a problem that the police alone can solve.