A gang of travellers thought to have been responsible for nearly half the country's caravan thefts over a three-year period were jailed today.

Family members Charlie Ward, 28, Martin Ward, 21, John McDonagh, 31, and Martin McDonagh, 29, were found to be in possession of more than GBP700,000 in stolen caravans, cars and motorhomes, jewellery and cash when they were arrested in Wiltshire in 2007, police said.

After they were detained, thefts of caravans fell from 848 to 454 in a year.

Winchester Crown Court heard the Ward-McDonaghs began stealing caravans from driveways and motorway service stations in 2004.

The men were found guilty of conspiring to steal after the three-month trial, but cleared of money laundering.

Fathers-of-five Martin McDonagh and Charlie Ward were sentenced to four years and five years to be served consecutively for two conspiracies.

John McDonagh and Martin Ward received four years for their part in one of the conspiracies.

Only around half of the value of the goods had been recovered by police.

Sentencing the men, Judge Patrick Hooton said the crimes had caused distress and anguish to the victims.

"This trial lasted for three months and during the course of it I heard evidence of repeated thefts of caravans and motor vehicles which in total could be described as theft on a grand scale repeated time after time after time."

The judge said the conspiracy was well organised.

"All four each in their own way, in particular you Charlie Ward and Martin McDonagh, were responsible for all this."

The men, who travel between the UK and the Republic of Ireland, showed no emotion as the sentences were handed down. All of them had previous convictions related to the theft of caravans.

Confiscation proceedings will now take place against the gang to seize their assets, the court was told, and the men were ordered to co-operate with detailing their worth.

Detective Inspector Matt Davey, from Wiltshire Police, revealed at the end of the trial officials from the insurance industry reported a 47 per cent drop in national caravan thefts following the gang's arrest.

Nineteen police forces were involved in the operation to catch the men.