The 500 pound World War Two device was picked up during dredging work.
Mum Releases 'Angels' Photo
The mother of two children murdered by their IRA bomb survivor father who then killed himself has released a photograph of ''her angels'' as an inquest opened into their deaths.
The bodies of Michael, 51, Ben, seven, and Freya Pedersen, six, were found next to a Saab 900SE convertible car in a tiny lane at Newton Stacey, near Andover on Sunday.
The children's mother, Erica Pedersen, released a photograph of herself with the two children along with the statement: ''My angels are in heaven now.''
Grahame Short, coroner for central Hampshire, opened an inquest into the deaths and heard evidence confirming the identities of the three deceased.
The Winchester hearing was also told that post-mortem examinations showed that all three died of stab wounds.
Mr Short adjourned the inquest to be resumed on a provisional date of December 5.
Mr Pedersen was a former army sergeant in the Household Cavalry unit that was hit by an IRA nail bomb in Hyde Park in 1982.
He had recently split from his wife Erica, who lives in Ashford, Middlesex.
Mr Pedersen, who had been living in Chertsey, Surrey, had taken the children to visit his father in Andover but failed to return the two youngsters to their mother by the pre-arranged time of 5pm.
The bodies were found lying behind the car at 6.15pm on Sunday by a walker, according to police.
Officers were tracing the family of Mr Pedersen, who had two other children from a previous relationship, when his estranged wife raised the alarm at 7pm.
The children's maternal grandfather, William Clifford, 67, from Buckinghamshire, said the family was ''extremely distressed'' by the deaths.
Mr Pedersen, who had two children from a previous relationship, wrote on Facebook on August 31 that he had split from his second wife Erica, 43, with whom he ran a haulage business called High Road Logistics.
He said: ''Worst day of my life.
''Sadly have split with Erica am absolutely distraught.''
The 1982 bomb attack hit as Mr Pedersen's unit was taking part in a changing of the guard ceremony.
Four soldiers and seven horses were killed in the explosion, which left Pedersen's horse Sefton seriously injured.
Despite 34 separate wounds that required eight hours of surgery, the animal survived and became famous for battling against the odds.
Sefton became a symbol of the struggle against the IRA and won the Horse of the Year, a prize Sgt Pedersen picked up on the animal's behalf.
640 men were killed when the South African troop carrier was hit by a cargo ship in 1917.
The 79-year-old man suffered a serious head injury in the Cranmer Road car park in Winton.
Two Girls Indecently Assaulted Last Sunday
Recently Played Tracks
On Radio: Rich and Zoe
6am - 10am
Text 'SOUTH' to 82122
Now playing: Non-stop hit music
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
What's happening on the roads where you are?
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart.
Get some great ideas on how to advertise your business on radio, online and on mobile.