Yorkshire Ripper Peter Sutcliffe spends hours replying to sack-loads of letters many of them from admiring women the Telegraph & Argus can reveal.

The 59-year-old Bradford serial killer, who is detained indefinitely at Broadmoor secure hospital, is wading through hundreds of letters from across the country and from abroad.

Sutcliffe, who was caged for life in 1981 for the murder of 13 women and trying to kill seven more, has such a backlog he says it is impossible to reply to them all.

His brother Mick Sutcliffe, of Bingley, who speaks to him by phone every week, said he had told him he could not keep up with the correspondence that pours in.

Mick said: "He has told me there are hundreds of letters stacked up. A lot of them are from women. He has had women writing to him for years. They seem to have a fascination for him because of who he is. It's amazing they would want to court a killer like Peter."

The Ripper also receives letters from people who had been detained with him and have been released.

Mick said: "He tries to reply to the people who write to him. He feels obliged to, and he enjoys it. It keeps his mind occupied. But he says he can't keep up with them.

"He can be writing all night. If I ask him if he is watching something on TV he often says that he has to catch up with his letters."

Sutcliffe also has two or three visitors a week, including his former wife Sonia and his fiancee Pam Mills, 54.

"Sonia goes to see him every few months, they are still good friends," said Mick. "Pam is a regular visitor. They have been engaged for years, though they have no intention of ever getting married. But they are still close and she still visits."

Sutcliffe, a former lorry driver, is also visited by penpals and former fellow patients.

And he spends hours on the phone.

"He is talking to somebody all the time. He is on the phone all day, every day. But when I speak to him it's usually just tittle tattle about what's on the telly, and the like."

A criminal psychologist claimed some of the women who write to Sutcliffe might be fascinated with him because they were suffering abuse or violence themselves.

Dr Colin Webster, a reader in criminology at Leeds Metropolitan University, said: "They could be interested in trying to get some insight from the horse's mouth. But Sutcliffe won't be capable of offering any insight. He would just give banal reasons for his motives.

"It doesn't surprise me that they would contact him, but I don't think it's a sensible thing to do. They won't find any solution. They are wasting their time."

But Mick Sutcliffe said some of the women who contacted his brother were using him to make money.

"There have been one or two who have got in touch and struck up a relationship and then written books about it," he said.

He said his diabetic brother, who has had weight and sugar level problems in the past, is now fit and healthy.

He said: "He goes to the hospital gym three times a week and his weight has come down. His diabetes is under control and he is cooking himself healthy food, like steak."

Sutcliffe was blinded in one eye when he was attacked by a fellow patient some years ago.

But Mick says he gets on well with other patients at Broadmoor.

He said: "He gets on fine with people and he has some good mates there. The years are passing by and he is just getting on with it."