The BBC has launched an investigation into Chris Packham over an alleged breach of impartiality rules after a complaint by the Countryside Alliance over his anti-hunting views.

The organisation made a complaint against the Springwatch presenter when he described those involved in hunting and shooting as "the nasty brigade" in last October's BBC Wildlife magazine.

Chairman of the Alliance, Simon Hart MP wrote to the BBC to take action, saying: "We cannot stand by and continue to allow Mr Packham to use the status the BBC has given him to spread propaganda which has a direct impact on the lives of our supporters."

A spokesman for the BBC Trust confirmed an investigation was launched in July following complaints by the Alliance and the Game and Wildlife Conservation Trust (GWCT).

It will assess whether Packham breached editorial standard guidelines and will publish a decision in September.

Packham, who is president of the RSPB, received a backlash for recently calling for a ban on driven grouse hunting.

Hampshire Police investigated threats made on social media against the TV presenter.

He has also invoked the ire of Sir Ian Botham for his anti-grouse hunting campaigning.

Botham told the Mail on Sunday, Packham damaged the reputation of the BBC's wildlife team for impartiality.

He added: "When next month the BBC Trustees announce their solution to their Chris Packham problem, they may tell him to spend more time with the birds, away from the cameras."

The former cricketer wrote that Packham "can not be convincingly neutral" and his comments "drags down confidence in the Corporation among rural communities".

Sir Ian, nicknamed "Beefy", has supported a campaign called You Forgot The Birds (YFTB) which claims to hold the RSPB to account.

Writing on his blog, Packham said he believed that YFTB was "a concerted attempt by shooting interests to manipulate government policy processes to try and get their demands met on grouse shooting by neutralising the RSPB and people like myself who side with them".