'Crazed fan wanted my head for his wall and Bee Gee tried to shoot me' says music legend

Smuggled around London in everything from ambulances and fire engines to hearses and rubbish trucks, The Osmonds were forced to take extraordinary measures to stay safe from hysterical fans.

So intense was 'Osmondmania,' that when the quintet of Mormon brothers from Utah, USA, flew into Heathrow in 1973, a viewing balcony at the airport collapsed after a crowd surge by some of the 10,000 waiting fans.

In an exclusive interview, Merrill Osmond, 72, who has just released his autobiography Black Bear – My Life Story, says Utah cops even armed them, after a fan threatened to decapitate him.

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Merrill, the lead singer on hits including Crazy Horses and Love Me for A Reason, tells The Mirror: "There were death threats and there was a guy who wanted my head for his wall.

"He was an eccentric fan. Thank goodness his wife tipped off the cops before he got to the hotel. We had security on tour, but when we got back home it got weird. Because of the continuous death threats, we were made policemen.

"Whenever I got a ticket on the road, I usually outranked the police officer that was stopping me! We carried weapons. We had to be armed to protect ourselves in case we were attacked. We were taught how to use guns - we had to be very aware."

The Osmonds were also warned that American terrorist group, the Symbionese Liberation Army, was after them.

Merrill says: "The threat was that if we didn't stop entertaining by a certain day, we would be executed. My wife Mary had to have security cars drive her wherever she went to make sure she wasn't kidnapped."

The Osmond brothers – Alan, Merrill, Wayne, Jay and Donny – were also given lessons by top martial arts expert Chuck Norris. "He got us into karate," Merrill recalls.

"So, on top of the fact that I was very knowledgeable in how to use a weapon, I knew that if I were to engage somebody on the streets hand-to-hand, I was pretty capable of handling myself."

The band shot to fame in the UK in 1972, with the release of Crazy Horses. The following year members of the Osmond family - who even had their own cartoon series - charted 13 UK singles, with Donny launching a successful solo career, along with sister Marie and younger brother Jimmy.

Recalling their chaotic reception in London during their 1973 visit, Merrill says: "The fans would think we'd be going out in limos, but we'd be hiding in ambulances, security vans, a hearse, a garbage truck, a milk truck, a fire engine and bread vans.

"The fire department were using hoses to squirt people out of the streets, so we could get out of the hotel. It was mind-boggling.

"Paul McCartney said to us 'you're not experiencing hysteria; you're experiencing mania and that is a completely different thing.'

"Backstage at one concert, there was a break in by a lot of the fans who attacked us. I was on the ground, my hair was coming out, my shirt was coming off.

"Every one of us was in that situation. It was very dangerous. My mother was there pulling people off. It was out of control."

Ironically, although the brothers were besieged by girls desperate to date an Osmond, Merrill was 20 before he had his first kiss - at the dentist's!

He recalls: "I was going on a date and I had no idea how to kiss and I figured I better get my act together.

"Anyway, the nurse at the dentist's was there listening to the whole conversation. When the dentist was done, she came up to me and said, ‘Hey, if you want to know how to kiss, I can help you. When the dentist leaves, come to the back door, and I'll let you in. Just sit in the dentist chair, and I’ll lower the seat and show you all the different techniques.'

"The funny thing about it was, when I finally went on a date with my wife Mary, she said I was the best kisser she had ever kissed!"

Amorous nurses were one of many temptations put in the Osmond brothers' path. "I've seen things I don't think any teenager should see," Merrill confesses.

"We were good ol' Christian boys and we came from the farm and the next thing we're thrust into the world of mania.

"There were prostitutes put in our rooms. Our manager tried to create all kinds of controversy to keep us in the press. They'd plant drugs in cars and hopefully try to catch us."

With 100 million album sales worldwide and further chart-topping hits including Let Me In and The Proud One, the brothers even counted Iraqi tyrant Saddam Hussein among their fans.

"When the military went in to get him, they entered one of the bunkers underneath his palace and they found a whole series of albums of our music. I don't know if that's a good story or a bad one!" Merrill laughs.

But as well as laughs, there has been a lot of sadness in Merrill's life. In Black Bear, he opens up about sexual abuse he suffered as a child at the hands of a tutor and is frank about his depression, anxiety, bipolar disorder, suicidal thoughts and bulimia.

"I've had three nervous breakdowns and I can only attribute it to the amount of information that was pounding at me at such a young age," he reflects.

"I'm a sensitive guy and I was dealing with real-life issues that a 20 year-old kid should not be facing. I also have a diabetic condition and other conditions that I don't talk about – it's taken its toll."

The Osmonds eventually broke up in 1980, although they have reformed several times down the years.

But Merrill says it's now finally over. His oldest brother Alan, 76, has multiple sclerosis, Wayne died last year, aged 73, and Jimmy, 62, is recovering from a stroke. Jay, 70, and Donny, 67, still perform, but as solo singers.

And Merrill – considered by many to be the heart of the group – says he will never sing again.

"I'm retired now," he reveals. "This was my last trip to England. I'm here to promote the book and say goodbye to so many wonderful people and then I'm going home.

"I'm going into another phase of my life. I'm with my sweetheart who has sacrificed her life to support me. I didn't have the chance to see a lot of my kids' football games, so I'm going to try to live my life through them, while the Lord still has me on this earth."

Merrill Osmon's autobiography Black Bearis available in hardcover