Russell Brand and Jonathan Ross are to be suspended and their shows taken off air until the BBC investigates their Radio 2 prank calls to Andrew Sachs.

The move by director general Mark Thompson comes as complaints to the BBC about the matter soared to 18,000.

He said: "I've decided it's not appropriate for either to continue broadcasting until I've seen the report of the actions of all concerned."

Mr Thompson described Brand and Ross's prank as a "gross lapse of taste by the performers and the production team, which has angered licence payers".

He added: "I'd like to add my own personal and unreserved apology to Andrew Sachs, his family and to licence fee payers for the completely unacceptable broadcast on BBC Radio 2.

"I am determined that any lessons are learnt and appropriate action taken."

Friday's edition of Ross's chat show, due to feature guests Frank Skinner and Miley Cyrus and the Killers has been cancelled.

Sir David Attenborough was also due to be a guest, but was "discussing the situation with the BBC" before the suspension of the two stars was announced.

Ross and Brand's Radio 2 shows this Saturday are also likely to be shelved.

The number of complaints to the BBC has nearly doubled overnight from 10,400.

The number is second only to the 2007 Celebrity Big Brother race row involving Shilpa Shetty and Jade Goody which received 45,000 complaints.

Georgina Baillie, 23, granddaughter of Sachs has said Ross and Brand should be sacked for their lewd phone calls. PM Gordon Brown has also condemned them for their behaviour.