A BBC reporter was in a “complete state of anxiety” while working undercover inside an immigration removal centre, a public inquiry has been told.

The inquiry is examining bullying and physical mistreatment of detainees at Brook House Immigration Removal Centre.

Callum Tulley, who was 18 when he worked undercover for the Panorama programme, said he constantly feared being caught by “hostile staff”. He wore a hidden camera while working as a detention custody officer. During 37 shifts at the centre near Gatwick Airport in West Sussex, he filmed a series of abusive incidents.

The Panorama programme revealed the bullying and physical mistreatment of detainees, some of whom had mental health conditions.

Mr Tulley, now a full-time BBC staff member, had contacted Panorama in 2016. He said he believed his concerns about what was going on would not be taken seriously by G4S, which ran Brook House at the time.

Mr Tulley said a poster informing staff about a whistleblowing policy was scrawled with graffiti warning about “snitching”. He has also told the inquiry managers were involved in some of the abuse, despite the fact that managers would have dealt with any complaints he might make. Mr Tulley said had planned to resign, but then decided to stay in the job after Panorama began to investigate his concerns.

“I was effectively a mole for the BBC for 14 months,” he said.

His job included dealing with suicidal detainees.

“While my mates had gone off to uni I was cutting ligatures and responding to self-harm incidents and witnessing abuse and it was having a detrimental effect on my mental health,” he told the inquiry.

Mr Tulley met BBC producer Joe Plomin each evening after his shift to hand over footage.

“I was as confident as you can be wearing secret cameras into prison with hostile staff,” he told the hearing.

“I’d be lying if I said I wasn’t in a complete state of anxiety [during] the two-and-a-half months that I was wearing secret cameras.

“Was that because of a lack of confidence? No, it was just a fear of being caught.”

He said he was working in “total secrecy”, not telling friends or family.

Mr Tulley was given a BBC-appointed psychiatrist to support his mental health.

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