Police officers and clergy in London were today advised how to recognise the signs of abuse suffered by children accused of witchcraft or "spirit possession".

The event, designed to raise awareness of child abuse linked to faith or belief, follows a year when the Metropolitan Police Service received a record 27 allegations relating to ritual child abuse.

The allegations ranged from child neglect through common assault, actual bodily harm, administrating noxious substances to sexual assault offences.

Out of the 27 investigations, one case has resulted in an arrest for rape and one in a charge for rape. Examples of the referrals include a child forced to drink unknown substances to rid them of demons, dunking children in a bath to wash away evil spirits, a pastor who swung a child around banging their head to drive out the devil and parents removing children from school and taking them out of the country to attend an exorcism ceremony to remove the evil spirits.

Other examples in previous years include chilli peppers being rubbed into the child eyes to remove the evil spirit.

Police, clergy, teachers and other agencies at the central London event were given a checklist of signs to look out for.

Children accused of spirit or devil possession or of witchcraft have displayed behaviour "consistent with distress", they were told. "They may appear isolated, quiet, withdrawn and sad. Significant numbers come to notice of teachers because of signs of neglect. Children come to school hungry, unkempt, dirty and in unlaundered clothes. Some come to attention because of injuries or because of aggressive behaviour or truanting," a spokesman for the event said.

The meeting, hosted by the Metropolitan Police Service and the Churches' Child Protection Advisory Service (CCPAS), included the launch of a training film aimed at all front-line professionals who work with children.

The DVD, commissioned by the Metropolitan Police's Project Violet team, set up in 2005 at the conclusion of a trial into the abuse of "Child B" in conjunction with CCPAS, offers clues on how to recognise signs that a child may be suffering, or is likely to suffer, significant harm from abuse linked to witchcraft and spirit possession.

Officers believe this form of abuse is rarely reported, and all agencies believe this is a hidden crime kept within families and faith communities.

Detective Superintendent Terry Sharpe, from the Metropolitan Police Sexual Offences, Exploitation and Child Abuse Command, said: "Abuse linked to belief is a horrific crime which is condemned by people of all cultures, communities and faiths. A number of high-profile investigations brought the issue of ritual abuse and witchcraft into the headlines but it is important that professionals are clear about the signs to look for.

"Families or carers genuinely believe that the victim has been completely taken over by the devil or an evil spirit, which is often supported by someone who within the community has portrayed themselves as an authority on faith and belief. Often in the perpetrators minds, any abuse is not going to affect the victim because he or she believes the child is effectively not there any more and the abuse is directed at whatever has possessed the child. The victim is often convinced that this is the truth and that the abuse is 'normal' behaviour.

"Regardless of the beliefs of the abusers, child abuse is child abuse. Our role is to safeguard children, not challenge beliefs. We investigate crimes against children, but our main aim is to prevent abuse in the first place. This is a hidden crime and we can only prevent it by working in partnership with the community. Project Violet aims to build trust with communities and emphasise that child protection is everyone's responsibility."

Simon Bass, head of the CCPAS, said: "CCPAS continues to work with churches to address all aspects of safeguarding, including abuse linked to faith or belief. We are therefore not remotely surprised that the MPS alone has already received 27 referrals of this type this year – or three a month.

"We are pleased that the Metropolitan Police Service has undertaken such great work in this area, but we are convinced that this form of abuse is hidden, and that the statutory agencies across the UK are facing similar situations - which is why we are so pleased that this new DVD is set to be a major new weapon in the ongoing fight to eradicate this type of abuse. This is because it will not only educate both front line practitioners and churches better but it will also emphasise that the only effective way to tackle it is by working together."

Kevani Kanda, a survivor of ritual abuse and presenter of the BBC Three documentary, "Branded a Witch", said: "As a survivor of ritual abuse I have witnessed at first hand the harm which belief-related abuse can result in. Globalisation means that paranoia over witchcraft and spirit possession is no longer confined to developing nations. Mass migration has made this a pervasive problem worldwide. It is not confined to cities or areas where there are large migrant communities. Belief-related abuse can result in significant physical, emotional harm, neglect, sexual abuse and even death."

Mor Dioum, director at the Victoria Climbié Foundation, and chair of the National Working Group on child abuse linked to faith and belief, said: "It is important that we do not shift the focus from this type of abuse, and essential that we implement the plan, to enable us to put the necessary measures in place to prevent children from death or serious injury as a result of abuse linked to faith or belief.

"We urge professionals to adopt a more holistic approach with children, young people and families when dealing with abuse that does not fit the norm, as we continue to raise awareness within the community with a view to increase the reporting of harmful practices."

There is no definitive list of religions that believe in or practise witchcraft. A belief in "spirits" and "possession" is relatively widespread but a spokesman for the event said there was no evidence to suggest that any community tolerated the abuse of children more than any other.

Children can be at risk when a family is experiencing difficulties and this is rationalised by the belief that they are cursed and the victim has become possessed by evil spirits. A victim may be perceived as "different" due to changes in their family structure or dynamics, or because of his or her physical, emotional, mental or behavioural problems.