The family of an elderly woman who was set on fire outside a block of flats in Watford have said that they are “desperate for answers”.

Brenda Raymond, 80, was found set alight outside her flat on Caractacus Cottage View on Monday. She was taken to a nearby hospital, where she is in critical condition.

Hertfordshire constabulary have said that a 33-year-old man was arrested on suspicion of conspiracy to commit arson with intent to endanger life but has been released on bail with strict conditions.

Raymond’s family said the attack had left them in “complete shock” and that they were confused over why she was targeted.

In a statement issued via Hertfordshire constabulary, they said: “Words cannot describe how distressing the past few days have been for us as a family.

“Our beautiful, chatty, fun-loving and much-loved Brenda, who loves to keep fit and dancing, has suffered catastrophic injuries in the most devastating of circumstances; circumstances which have left us all in complete shock.

“We simply cannot understand why anyone would have wanted to hurt her in this way. Someone out there knows something. They know what happened to Brenda. We are desperate for answers and are pleading for anyone with information to please come forward.”

The family also asked for their privacy to be respected during this “unimaginably difficult time”.

Police believe that Raymond was attacked as she returned home at around noon, with her attackers pouring some kind of flammable liquid on her before setting her alight. Detectives said that an accelerant was also poured through the letterbox of a nearby flat, but have not officially linked the two events.

The decision to publicly name Raymond was made by police with the blessing of her family on Wednesday in the hope that it would lead to anyone with knowledge of the attack coming forward.

DI Adam Bridges, from the Major Crime Unit, said: “This was an appalling and deeply distressing attack on an elderly woman who suffered horrific injuries after being set alight outside her own home.

“Our thoughts very much remain with Brenda and her family as we continue to do everything we can to find out what happened and who is responsible.

“Her family are understandably distraught and have taken the step of releasing her name and photograph to help jog people’s memories around this distressing and highly unusual incident.

“Someone out there knows something. You may have witnessed suspicious activity, heard a conversation, noticed unusual behaviour, or captured something on CCTV or dashcam footage without realising its significance.

“Please do not assume that what you know is too small or unimportant to tell us about. It could be a seemingly insignificant piece of information that provides investigators with the breakthrough they need.

“If you know anything about what happened to Brenda or think you may have information that could assist our inquiries, please come forward. Your information could be crucial in helping us find answers and bring those responsible to justice.”