The record breakers in the news today

UK sunbathers have been warned to take extra care following a rapid rise in jellyfish blooms around Britain's coasts.

The Marine Conservation Society says the recent warm weather coupled with a cold spring has caused an explosion in numbers over recent weeks of several species including the Lion's Mane.

Most jellyfish have a bell or body diameter ranging from 2 - 40 cm (0.8 - 15.8 in), but some species grow considerably larger, with the largest species being the Arctic Giant (Cyanea capillata arctica).

The largest jellyfish ever recorded was an Arctic Giant that was washed up in Massachusetts Bay, USA in 1870 which had a bell diameter of 2.28m (7 ft 6 in) and tentacles stretching 36.5 m (120 ft).

A trio of songs recorded by Michael Jackson and Queen singer Freddie Mercury in 1983 are due to be officially released for the first time.

Mercury's bandmate Brian May is working on mixing the tracks alongside Queen drummer Roger Taylor and producer William Orbit after being given permission by Michael Jackson's estate to release the recordings.

A concert held at Wembley Stadium, London, on 20 April 1992 in memory of Freddie Mercury who died the year previously, raised $35 million [£19.96 million] for AIDS-related charities. Attended by over 75,000 people and watched by a TV audience of almost 1 billion in over 70 countries, the gig is recognised by Guinness World Records as the largest rock star benefit concert of all time.

A violinist has been reunited with a rare violin worth £1.2m that she had stolen from her over two years ago.

The 300-year-old Stradivarius was swiped from internationally-renowned musician Min-Jin Kym in 2011 when she was in a sandwich shop near Euston Station in north London.

The most expensive musical instrument sold at auction is a violin known as the “Hammer”, made in 1707 by Antonio Stradivari in Cremona, Italy, which sold for $3.5 million (£1.8 million) to an anonymous buyer, at Christie’s, New York City, USA, on 15 May 2006.

It is one of 620 instruments made by Stradivari thought to exist.

Finally, a new documentary has claimed US President John F Kennedy was killed by “friendly fire” from a clumsy secret service agent who was supposed to be looking after him.

JFK: The Smoking Gun names George Hickey as the man riding in the car behind Kennedy when he accidentally fired his weapon on November 22, 1963.

The shooting of Lee Harvey Oswald (USA),­ the man accused of killing Kennedy,­ by Jack Ruby (USA) on 24 November 1963 was broadcast live on national television and is the first known human killing seen live on TV.