Eight people have died and four are injured after a minibus and two lorries crashed on the M1 in Buckinghamshire this morning.
Police also arrested a 53-year-old man from Stoke-on-Trent on suspicion of causing death by unsafe driving.
Two men have been arrested on suspicion of causing death by unsafe driving, both are now in custody.
It was reported on Saturday that a man, a woman and a five-year-old girl were being treated for life-threatening injuries, while another woman was in hospital in a less serious condition.
It is thought the minibus had travelled from the Nottingham area, Thames Valley Police (TVP) said.
Masierak, 31, will appear High Wycombe Magistrates Court on Monday, while Wagstaff, 53, will appear before Milton Keynes Magistrates Court on September 11. Those killed and injured were believed to be in the minibus. He had been taking a group of people from India to London from where they were due to start a tour of Europe. "We don't want him to part us because he was part of every part of our lives".
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The driver of the minibus, who died in the crash, has been identified as Cyriac Joseph.
In a Facebook post he wrote: "Hearty condolences".
A spokesman for FedEx said: "We are aware of the tragic accident that occurred last night on the M1 motorway, junction 14 in the United Kingdom with a FedEx truck involved". Our thoughts are with the families at this extremely sad time.
"We will continue to provide all assistance to the families in this hour of grief".
A picture taken by a driver shows two lorries smashed up by the side of motorway (left) while another passenger captured the congested traffic as thousands have been forced to divert their routes. Broken glass and debris from the collision was scattered across the tarmac.
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