Jimi Heselden, who has left an estate of more than £340m to his family, died in a cliff fall. His Sedgway scooter was found nearby. Photograph: Andy Paraskos/PA

A businessman who died while apparently riding a Segway scooter built by his own company has left an estate of more than £340m to his family.

Jimi Heselden, 62, was found in the Wharfe river at Boston Spa, near Wetherby, West Yorkshire, after falling from a 30ft cliff in September 2010. His Segway was found nearby.

Heselden, who was one of the 400 richest people in the UK, has left an estate of £343,172,206 to his widow, Julie, and other family members.

His Leeds-based firm Hesco Bastion developed the "blast wall" basket, used as a replacement for sandbags to protect soldiers in Afghanistan and Iraq.

The units have been used in every major conflict since the first Gulf War and are seen as one of the UK's most successful defence exports. They are also used for a range of non-military functions including flood management and erosion control.

In December 2009, Heselden led the British team that bought the US-based Segway firm, which makes and distributes two-wheeled, self-balancing scooters.

A former miner who left school when he was 15, Heselden was known for his charity giving. The Leeds Community Foundation said he had donated £23m to causes in his home city since 2008. He was also closely linked to the Help For Heroes charity, which supports injured military personnel.

The trustees of Heselden's estate said it consisted substantially of his controlling interest in Hesco Bastion Ltd.

"The family wishes that Jimi's legacy will live on in the many charities and good causes he supported during his lifetime," they said.