The growing popularity of the BBC's on-demand video service iPlayer yesterday sparked a further war of words in the row between the broadcaster and internet service providers over who should pay for the increased strain being put on networks by the device.

The latest figures show that use of the BBC's playback video service has risen by 25% a month, with the total number of requests for downloads and streams of BBC programmes in March hitting 17.2 million, rising from 14 million in February and 11.2 million in January.

But ISPs have been raising concerns about whether the internet can cope with the popularity of the video service.

Last week, the BBC threatened to name and shame ISPs that attempted to restrict downloads from its iPlayer, a move criticised by the internet companies as "aggravating a difficult situation".

Regulator Ofcom has warned that the cost of renewed infrastructure required to support such services could amount to £830m by 2011.

Yesterday ISPs said they were concerned that they were being expected to pick up the cost of increased traffic that such TV-on-demand sites were placing on internet networks.

Simon Gunter of ISP Tiscali told the BBC's Today Programme: "The BBC would like us to pass all those costs on to the end user - our customers, the consumers of that product.

"And our view is that Should we pass all those costs on to the end user or should we seek to somehow share those costs with the content originators'?"

Ashley Highfield, director of future media and technology at the BBC, said of helping internet companies out: "I don't think that's what the BBC is funded to do."

He told Today: "I really think that the BBC should be there to create great content and to get it into the network and that the broadband service providers should get it to people's homes to deal with a simple billing structure so that they are the ones that charge for internet service provision to their customers and that the BBC shouldn't get involved in that end of it."

Geoff Bennett, of Infinera, which helps build the internet's infrastructure, said that instead of a typical internet application, which works in short, sharp bursts, the iPlayer is "sustained traffic on the network".

He told Today the solution was: "You deal with the bottleneck. It does take money."

More than 42 million programmes were accessed on demand since the Christmas marketing launch, the BBC said.

Average weekly users of BBC iPlayer reached 1.1 million in March, up from January's average of 750,000 users.

The first episode of The Apprentice was the most streamed BBC programme on BBC iPlayer in its first three months.

Meanwhile, a collaboration to offer BBC iPlayer via the Nintendo Wii was unveiled yesterday.

Erik Huggers, the BBC's group controller for future media and technology, made the announcement in a keynote speech at a conference in Cannes.

Mr Huggers said that as of today Nintendo Wii users can stream their favourite BBC programmes via the console.



Top 10

The top streamed programmes were:
1 The Apprentice BBC1 March 26 2008
2 Louis Theroux: Behind Bars BBC2 January 13 2008
3 Ashes to Ashes BBC1 February 7 2008
4 Torchwood BBC3 March 21 2008
5 Dawn...Gets Naked BBC3 February 14 2008
6 Torchwood BBC2 January 16 2008
7 Doctor Who Voyage of the Damned BBC1 December 25 2007
8 Torchwood BBC3 February 20 2008
9 Gavin and Stacey BBC3 March 23 2008
10 Dawn...Goes Lesbian BBC3 February 21 2008