An NHS trust has come under fire after two patients with violent pasts detained under the Mental Health Act escaped from one of its wards last week.

Less than two months ago another of its patients, from a different ward on the same site at Epsom Hospital, managed to climb a high chimney nearby before falling to his death.

Surrey and Borders Partnership NHS Foundation Trust is now carrying out two internal investigations to establish what can be learnt from last week's escapes and the fatal fall of Adam Withers, 20.

The two absconders got out of the hospital on Wednesday morning without the medication needed to control their mental illnesses.

Despite the men's violent past, a police appeal was not issued until nearly 36 hours later and on Friday the men were captured separately in Aldershot and Dorking thanks to information provided by the public.

Police failed to explain exactly why they held off issuing the appeal, except to say that they evaluate each case carefully, deployed officers immediately and used "every effort" to find the men for 24 hours before deciding to go public on Thursday evening.

Nigel Collin, a concerned father, local resident and chartered accountant, said: "The latest lapse in security beggars belief and cannot be ascribed solely to lack of resources.

"It was precisely this poor housekeeping which allowed Adam to climb the tower. Given that Chris Grayling is the local MP and his position in the coalition, he should be required to obtain a detailed assessment from Jeremy Hunt."

Councillor Neil Dallen, who represents town ward, said he was "disappointed" that the safety and security of the patients and the wider public had been put at risk.

Coun Dallen said: "I would hope they would put some procedures in place to stop it happening again. There’s something wrong in the system for that to happen.

"Once is possibly an accident or human error but more than once means there are not enough procedures and processes in place."

On the timing of the police appeal, he said: "To wait 36 hours seems very slow. I would want to find out why before criticising it too much but on the face of it, it does not seem like a good service to the public.

"An appeal to catch them is also an appeal to be aware, to keep people safe."

Andrew Wills, a long-time resident of Epsom, said the area’s former psychiatric hospitals have now been replaced by smaller mental health wards.

Mr Wills asked: ""Do the authorities look very carefully at which people are suitable for this sort of environment? Are these places meant to be secure? If they are meant to be secure, are they secure? And if not why not?"

Jane Shipp, from health watchdog Healthwatch Surrey, said they were concerned about the trust's "duty of care" to the absconders who had been detained for their own safety.

Ms Shipp said they have asked to be updated on the progress of the NHS trust’s investigation and specified that it must be carried out in a timely manner.

She said: "We have high expectations of a thorough investigation being done and quickly so there can be an understanding of this very soon.

"We would like what happened to come to light as quickly as possible so things can be learnt. We are looking for it to be dealt with quickly and transparently."

She declined to comment on the fatal fall in relation to the abscondment on Wednesday. She said: "He was not detained in a secure way. They are two different sets of circumstances."

On Friday, Andy Erskine, director of mental health and social care at the trust, said: "We would like to thank Surrey Police and the public for their support in locating these two vulnerable men whose wellbeing we were very concerned for.

"We are conducting an internal investigation to establish how the men left the ward to ensure that lessons are learnt to minimise the chances of this happening in the future."