Brotherhood with history of bad blood

Police investigating the murder of motorcyclist Gerard Tobin who was shot dead on the M40 in Warwickshire have said biker gangs are a "strong line of inquiry". But who are these biker gangs?

Gerard Tobin, originally from Canada, had lived in the UK for 10 years

Gerard Tobin is believed to have been a member of the Hells Angels, who are by far the most famous, or infamous, biker gang, but they are not alone on Britain's highways.

Other gangs include the Bandidos, Pagans, Outcasts, Outlaws, Cycle Tramps, Scorpios and Ratae.

But it is the Hells Angels who remain the most famous group, with an estimated 1,800 members in 22 countries.

They were formed in 1948 and took their name from a World War II US air force bomber squadron.

They have been involved in some extremely violent incidents - several in the UK.

Sunday's shooting bears similarities with an incident in 2001 when a Canadian man was shot in the leg as he rode his motorbike down the M40 towards London after also spending the weekend at the Bulldog Bash.

Turf wars

In 1998, two bikers were left dead when 40 Hells Angels ambushed rivals the Outcasts at the Rockers' Reunion in Battersea, south London.

Wielding axes, knives, hammers, coshes and baseball bats, they brought a bloody end to a year-long feud between the gangs.

Hells Angel Ronald "Gut" Wait was eventually jailed for conspiring to cause grievous bodily harm.

The Hells Angels form a tight bond between its members

In Mr Tobin's native Canada biker gangs are often associated with drugs and violence.

The Criminal Intelligence Service Canada says the Hells Angels are the foremost organised crime group in the country.

A particularly violent drugs feud in Quebec between the Angels and another gang, the Rock Machine, claimed 150 lives in the late 1990s, including that of an 11-year-old boy who died when a car bomb exploded outside a biker hangout.

Last year eight men - members of the Bandido gang - were found dead in a field near Shedden, a hamlet in the Canadian province of Ontario.

Fights between rival bikers take place the world over, often over criminal activities such as prostitution and drug smuggling.

During the mid-1990s, a "biker war" was waged between the Hells Angels and the Bandidos in Scandinavia which cost numerous lives.

The myth that is very strong in the UK is that the Hells Angels are just a bunch of loveable rascals on motorcycles Julian Sher, author

The violence reached its crescendo in 1996 when two people were killed and 19 injured when an anti-tank missile was fired at a Hells Angels clubhouse in Copenhagen during a party.

In America, there have been many incidents of fighting, shootings and murders between rival gangs.

According to an FBI report in 2005, the Hells Angels take in $1bn a year worldwide from drug trafficking.

'Loveable rascals'

For many years the Hells Angels were led by Ralph "Sonny" Barger who, when interviewed by the BBC News website in 2000, played down the allegations against the Hells Angels as "FBI propaganda".

Australian Bandidos riding at a funeral in June

But investigative journalist Julian Sher, author of Angels of Death: Inside the Bikers' Empire of Crime and The Road to Hell: How the Biker Gangs are Conquering Canada, said the British wing of the Hells Angels should do more to disassociate themselves from their comrades across the Atlantic.

He said: "The myth that is very strong in the UK is that the Hells Angels are just a bunch of loveable rascals on motorcycles.

"The important thing to remember is that it is a world-wide organisation whose members have been charged with serious crimes from extortion to racketeering.

"They are members of a gang renowned for its violence and the British Hells Angels cannot say they have nothing to do with it."