First there was Casualty. But the next blow to Bristol could be the removal of Being Human to South Wales.

The Bristol Evening Post has been told by a reliable industry insider that the popular BBC series about a haunted Totterdown house is set to move production to Swansea.

There was uproar earlier this year when it emerged that the BBC planned to move production of its long-running drama Casualty to Cardiff – at an estimated cost to the city of £25 million each year.

But with filming currently taking place in Bristol for series two of Being Human, the rumour of a planned move for the show is a blow to the television industry in the region.

It comes just days after a visit to the city by Mark Thompson, director general of the BBC, who promised to continue developing a special relationship with the city by signing a memorandum of understanding – pledging that the Beeb would develop its investment in Bristol over the next three years.

The insider who spoke to the Bristol Evening Post said the show's stars, Russell Tovey, Lenora Crichlow and Aidan Turner have already been told that they will find their familiar caravan dressing rooms parked up in Swansea for the filming of a third series.

BBC press officer Lyndsey Honour denied the reports. She said: "A third season has not yet even been officially commissioned. They are still filming series two.

"Though we hope there will be a third series, no decision can have been made as to where it will be filmed, given that it has not yet even been commissioned."

South West Screen, the Government agency set up to support filming in the region, refused to comment on the rumour at what is undoubtedly a sensitive time in its relationship with the Beeb, given the recent "memorandum of understanding".

Writer Toby Whitehouse fought for Being Human to be set in Bristol – as a BBC Wales commission, there was always a strong desire for the series to be filmed in the principality.

"It was a BBC Wales commission," he recently told the BBC Writer's Room website. "Imagine a circle radiating out from Wales. We had to do it in Wales or a very limited number of other places. We couldn't have set it in Scotland or Brighton or anything like that as it was a BBC Wales show.

"Because it seemed as though every single drama was happening in Cardiff – Doctor Who and Torchwood and so on – we thought Cardiff was getting a bit crowded. So we decided to set it in Bristol."

Toby says there is a darkness to Bristol's history that also lends itself to the show. He said: "There's a scene in the first series when Mitchell is asked why he's settled in Bristol, and he talks about the slave trade and so on. So it seems like the right kind of place for him."