Some of the people who spoke to ITV News about alleged security breaches by G4S staff were sacked by the G4S and have tribunal cases against the company.
The man in charge of the operation, the G4S Managing Director of Global Events, Ian Horseman Sewell, rejected all their claims:
"At no point is there any evidence that dogs that have been trained to detect substances other than explosives have been used to try to detect explosives."
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England cricket coach Trevor Bayliss has described match-fixing claims around a Chennai test match against India in 2016 as 'outrageous'.
England have been beaten by nine wickets against Pakistan in the first Test at Lord's.
Mayor of London Sadiq Khan is backing the scheme.