UK Mail has declined to say what changes it has made to its operation since staff at one of its depots were shown on television mistreating customer consignments.

In a report broadcast on 29 April last year, Channel 4’s Dispatches secretly filmed staff at UK Mail’s Bournemouth depot throwing and kicking parcels marked ‘fragile’ around, sweeping parcels off conveyors to floor level, and leaving boxes stacked precariously on the floor.

Staff at the depot were also filmed talking about taking partly damaged consignments away for personal use, or to auction off online.

A spokeswoman for UK Mail told at the time that it took evidence of poor service “very seriously” and had launched an investigation into the programme’s findings.

However, this week after followed up the story, a spokeswoman for UK Mail simply said: “The matter has been looked into internally and is now closed. The findings of the investigation are now confidential."

Further enquiries have so far gone unanswered.

UK Mail’s position contrasts with TNT Post, which was also featured in the Dispatches report. Undercover filming for the programme revealed some postmen leaving mail unsupervised for long periods in bicycle panniers. These were not locked to bikes, which themselves were not well secured.

A spokesman for the company told us last week that TNT Post had added a further lock to its bicycles, locking the panniers to the bike, and made the pannier lock itself more secure.

The firm is also moving to a new pannier that has further security improvements, he said.

Both firms described the Dispatches programme as not representative of their operations at the time.

TNT Post has found itself in the spotlight since: last week, a BBC London News report again called its practices into question after piles of confidential post were found dumped in a bush in north London.