Pet ownership has rocketed since the covid pandemic, but so have vet prices. In fact, bills have increased by more than 60% in the last ten years. The Competition and Markets Authority is so concerned about the increases it has a launched an investigation into the industry and is due to reveal its findings this year. Datshiane Navanyagam investigates the pet industry and the corporate takeover of high street vets – talking to whistleblowers about how they feel they're being measured on the amount of money they bring in.

Reporter: Datshiane Navanayagam

Every year the UK produces around 50 million tyres for disposal. They’re supposed to be sent for recycling. Instead, big money is being made by diverting tyres to illegal and dangerous 'pyrolysis' plants they're melted down to extract oil and steel. File on 4 Investigates, together with a team of journalists from Source Material, a not-for-profit group specialising in climate and corruption, follow the tyres from the UK to India using tracking devices. The team discovers just how large scale this largely illicit business has become. Earlier this year, a makeshift pyrolysis plant exploded near Mumbai, killing four people. It had been processing tyres from abroad, almost certainly Europe and the UK. Reporter Paul Kenyon confronts a tyre trader in the north of England who admits to shipping his waste tyres to India for pyrolysis.

Reporter: Paul Kenyon

At least two women are murdered every week in the UK in a domestic abuse situation. Newspapers often call it a crime of passion. ‘He lost control’. But what if that’s not true? What if there was a blueprint that, if recognised, could save a woman’s life?

The Homicide Timeline contains eight stages that track the escalation of a controlling relationship from before a couple even meet right up to homicide. Families often say “I wish I’d known”. This programme will tell them the signs to look out for so that they do know, and can stop it.

File on 4 Investigates tells the story of Kasibba – a woman locked up as a schoolgirl in a mental health hospital. She languished there for 45 years - despite not being mentally ill. She was finally freed two years ago after the intervention of a rookie psychologist. Reporter Carolyn Atkinson asks why so many autistic people and/or those with a learning disability, including children, are still locked up and why successive governments have failed to meet their promises to move people from hospital to home.

Reporter: Carolyn Atkinson

File on 4 Investigates goes to Burnley in Lancashire to meet the young people and their families as they grapple with a ketamine epidemic.

Reporter: Jane Deith

With the billions he made at the expense of Russian taxpayers, Roman Abramovich bought six luxury superyachts over the years. Among them were the 162-metre-long Eclipse, with swimming pools, helipads and a missile defence system - and the Pelorus - sometimes lent to Chelsea footballers.

They could each cost up to one and a half million dollars just to re-fuel. If they’d been declared as being for his own personal use, VAT would have been payable on costs like that. Instead, for more than a decade, tax authorities were led to believe the superyachts were being rented out to commercial customers.

Reporter: Andy Verity

Tens of thousands of children and young people across the UK suffer from severe forms of epilepsy which are resistant to treatment.

Michael Buchanan examines why the University Hospitals Sussex NHS trust, once considered one of England’s best, has now got the largest number of patients waiting over 18 months for treatment. On top of this there is a growing police investigation into allegations of poor care.

Rporter: Michael Buchanan

The BBC's religion editor Aleem Maqbool hears from sexual abuse victims who say they were let down by senior church leaders for decades. Priest David Tudor was allowed to continue working within the Church of England - despite widespread concerns about his behaviour. Now there are calls for the Archbishop of York, Stephen Cottrell to resign over his handling of the case. He is due to take temporary charge of the church in the New Year following the resignation of the Archbishop of Canterbury, Justin Welby. The Church of England says File on 4's investigation into the case of David Tudor has 'revealed a catalogue of past safeguarding decisions, that allowed someone who was considered a risk in the 1980s to return to ministry in the 1990s.' This, they say, should never have happened.

Reporter: Aleem Maqbool

Universities in the UK are facing a financial crisis, and with fears some may become bankrupt many institutions are making savings by cutting courses and staff numbers. Falling numbers of international students, who pay higher fees than their domestic counterparts, is partly to blame for the funding gap. File on 4 investigates if universities have become too reliant on overseas students, in some cases favouring the ability to pay over academic ability and overlooking the poor English language skills of some of those they enrol - even ignoring concerns over cheating. It also hears from a whistleblower about the multi-million-pound recruitment industry that feeds students from abroad into universities here – all at a cost.

Reporter: Paul Kenyon