Linney will join regulars Duncan Bannatyne, Peter Jones, Deborah Meaden and another new Dragon, Kelly Hoppen.

BBC: Dragons' Den announces Piers Linney as new member

The other test cases concern actor Jude Law, sports agent Sky Andrew, interior designer Kelly Hoppen and MP Chris Bryant.

BBC: Paul Gascoigne becomes hacking test case

Earlier, he added that of Sheila Henry to a list including actor Jude Law, MP Chris Bryant, interior designer Kelly Hoppen, sports agent Sky Andrew and ex-footballer Paul Gascoigne.

BBC: Hacking MPs recall News International's James Murdoch

Haulage firm boss Hilary Devey left the show last year for her own Channel 4 series and interior designer Kelly Hoppen was announced as a new dragon last month.

BBC: Dragons' Den announces Piers Linney as new member