Innocent people are being wrongly convicted and criminals are escaping justice because of the failure of the forensic science system to meet basic standards, the regulator has said.

Delivering a stark message before the release of her annual report on Tuesday, the forensic science regulator, Dr Gillian Tully, told the Guardian the service had been operating “on a knife-edge” for years.

She warned of wide-ranging problems threatening the safety of justice, saying that too few providers are meeting the quality standards that were meant to stop errors.

Tully revealed that in England and Wales, not one CCTV image analyst met the required standard.

She accused the government of failing to give the regulator powers to enforce standards in the cash-strapped system, where private and public providers offer services that are the lifeblood of the criminal justice service.

Tully said: “Are there errors making their way through the system? Yes, there will be. Without quality assurance in place, you are not going to find the errors and the problems.” Evidence from some experts testifying in court was not scientifically justifiable, she said.

The current system, a marketplace of private and public providers, came about after the coalition government allowed the loss-making Forensic Science Service, then the primary provider, to collapse in 2012.

Tully said that led to some improvements but also to enduring problems, highlighted in her report.

Meanwhile, a lack of funds coupled with an explosion in digital evidence have led to parts of the forensic science system operating at or beyond its capacity.

Tully said: “Forensic science has been operating on a knife-edge for years, with skills shortages in digital forensics and toxicology, and choices to be made between operational deployment on one hand and making sure the basic quality-assurance measures are in place on the other.”

“If you fail to find information on a mobile phone, which could be critical on a decision on whether to proceed with a trial, that is in essence a miscarriage of justice,” she said.

Among the areas of concern is CCTV, crucial to many police investigations. The forensics regulator said she could not vouch for the accuracy of analysis meant to show if someone caught on camera was the same person as a suspect. “I can’t give an assurance about it in any case,” Tully said. “People are not fully tested according to international standards.”

An anonymous reporting line run by Crimestoppers last year received 65 complaints, a record number.

Tully said those complaints referred to her office came from better companies where people recognised and reported errors. “The bigger worry is those without proper assurance in place. It is the people who don’t have quality standards in place, that’s where errors slip through.”

This year the police had to put in more money to avoid the collapse of forensic science companies. In her report, Tully warns of wider risks: “Quality does not exist in a vacuum: the governance, funding, procurement and provision of forensic science all impact on the quality of provision.

“Achieving accreditation to a quality standard is neither the beginning nor the end of improving quality. Engendering a real culture of quality requires ongoing leadership and investment in people, processes and innovation. Therefore, the instability that has continued to be seen in this reporting year represents a significant risk to quality.”

Tully criticised the government for failing to honour commitments to give the regulator the power to force change. “Legislation is urgently required to give the regulator statutory enforcement powers,” she said.

The seven-year delay between giving assurances about providing statutory powers and the present time has previously been described by the House of Lords science and technology committee as “embarrassing” and by the House of Commons science and technology committee as a failure of leadership.

“It can only now be interpreted as a lack of priority being given to forensic science quality by the government,” Tully said.

The report also says in one instance software meant to secure digital evidence, such as from a mobile phone or other electronic device, made a serious error. “Although failure to find data is the more common issue, there is a risk that the tool may perform poorly in other ways,” it reads. “The most serious referral was where the tool incorrectly attributed the recipient of deleted messages.”

Digital forensics had a “a woeful level of compliance with achieving quality standards”, with those trying to gather digital evidence underresourced and overstretched, the regulator found.

Problems with crime scene investigators raises a continuing danger to contaminating scenes of offences, and there is a shortage of toxicologists in England and Wales, needed to determine when someone is poisoned, or how much drink or drugs someone has consumed.

The report reveals that more than 1,100 profiles stored on the national DNA database were contaminated by police officers and staff, and needed to be removed.

A Home Office spokesperson said: “We are strengthening forensics by boosting investment in digital capabilities and working with the police at a national level to develop innovative new solutions.

“Our aim is to make forensics work to a higher standard so it better serves the public by bringing criminals to justice. The criminal justice system must have the full confidence of the public.”