A court has heard how a former Somerset policeman was three times over the French drink-drive limit when his jeep crashed near his home in France.
Eight people were in the Jeep at the time of the crash, the inquest heard
Keith Bridges, 50, survived but four others were killed and a further four people were seriously injured.
Taunton Coroner's court heard when Mr Bridges took his foot off the accelerator the car did not slow down.
Coroner Michael Rose adjourned the inquest so allegations of mechanical failure could be investigated.
French police report
Mr Bridges a retired inspector with Avon and Somerset Police, survived the crash but his wife Julie-Ann, 43 and step daughter Bethany Lowe, 10, were killed.
Family friend Andrew Dyer, 41, from Bridgwater, Somerset and his daughter Gabriella, 10, also died in the crash.
The Dyer family had been enjoying a two-week holiday with the Bridges.
The inquest heard eight people had been crammed into Mr Bridges' Cherokee jeep at the time of the crash.
On the evening of 7 June, 2006 the two families were returning home after visiting friends who lived 2km away.
But while approaching a bend, the jeep left the quiet rural road and crashed into woods at high speed.
The children Gabriella and Bethany, who had not been wearing seatbelts died instantly, the French police report revealed.
The report confirmed that Mr Bridges, was three times over the French drink drive limit of 50mg alcohol per 100ml of blood - almost twice over the UK legal limit.
Mr Bridges, who moved with his family to France in 2005, blamed the crash on an alleged vehicle defect.
In a written statement read to the court, he said that while approaching the bend he had put the jeep into overdrive mode which should have reduced the car's speed.
But he said as he took his foot off the accelerator the jeep did not slow down.
The inquest is expected to resume in six months.
Mr Bridges is being investigated by French police in connection with the crash.