Russell Brand has resigned from his BBC Radio 2 show over the "Sachsgate" row, after an extraordinary day in which he and Jonathan Ross were suspended by the corporation.
Brand's resignation came just minutes after Ross spoke publicly for the first time about the affair, saying he is "deeply sorry" for his "juvenile and thoughtless remarks".
Brand and Ross's statements came as the BBC confirmed that it had now received 27,000 complaints about their prank calls - up from 18,000 this morning.
In his resignation video statement, standing beside what appeared to be a portrait of Stalin, Brand said he took "complete responsibility" for the prank phone calls he made with Ross to 78-year-old former Fawlty Towers actor Andrew Sachs and that he got "caught up in the moment".
In the messages, pre-recorded and broadcast on Radio 2 late on Saturday October 18, the pair alluded to Brand having had sex with Sachs' granddaughter, Georgina Baillie.
Brand apologised to both Sachs, "a beloved and brilliant comic actor", and Baillie, "a very sweet and big hearted young woman", and his "loyal listeners".
He also said he hoped "now that Jonathan and the BBC will endure less forensic wrath".
In Ross's apology the presenter said the prank calls were a "stupid error of judgment".
It is understood that Brand did not want things to escalate further and so decided to resign.
He is not as closely associated with the BBC as Ross, with a burgeoning film and comedy career on other UK channels and in the US. Brand is reportedly now on his way to Los Angeles.
"I have apologised to Andrew Sachs for the rude messages I left on October 18 and he has graciously accepted," Brand said.
"As I only do the radio show to make people laugh I've decided that given the subsequent coverage I will stop doing the show," he added.
"I've loved working for the BBC and am very proud of the shows myself, Matt Morgan, Nic Philps, Mr Gee and Noel Gallagher have made and I apologise to all of them for damaging their careers - except Noel, whose band are doing quite well.
"I got a bit caught up in the moment and forgot that at the core of the rude comments and silly songs were the real feelings of a beloved and brilliant comic actor and a very sweet and big hearted young woman.
"Apologies are also owed to the loyal listeners of the show who enjoyed its shambolic spirit and anarchy and will be upset that it cannot continue.
"I take complete responsibility and offer nothing but love and contrition and I hope that now Jonathan and the BBC will endure less forensic wrath. Hare Krishna."
Ross said he had previously not made a public apology as he intended to make one on his BBC1 chatshow, Friday Night with Jonathan Ross, which was due to be recorded this evening.
However, the show was cancelled earlier today after the BBC suspended both Ross and Brand over the row, pending the outcome of an investigation - the preliminary findings from which are due to be presented to the BBC Trust by the director general, Mark Thompson, tomorrow.
"I am deeply sorry and greatly regret the upset and distress that my juvenile and thoughtless remarks on the Russell Brand show have caused," Ross said.
"I have not issued a statement previously because it was my intention and desire to offer an apology to all those offended on my Friday night programme," he added.
"However, it was a stupid error of judgment on my part and I offer a full apology."
Sachs said of Brand's decision to quit: "I respect his decision. I hope he moves forward, I really hope he does."
Baillie told the Sun she was "thrilled" the pair had been suspended and that "justice has been done".
A parliamentary motion criticising the prank calls has also been signed by 13 MPs.
The BBC has spent the day battled to bring the row under control, announcing that it was suspending Ross and Brand, with their shows - Friday Night with Jonathan Ross and Ross' Saturday morning Radio 2 show and Brand's Saturday night Radio 2 programme - taken off air.
Thompson, who is flying back from holiday in Sicily this evening to take control of the situation, is due to receive a report by director of audio and music Tim Davie into the row. Davie is overseeing the BBC internal inquiry into the incident.
The director general will then present the inquiry's preliminary findings - and what action he intends to take - to an emergency meeting of the BBC Trust editorial standards committee tomorrow.
Sir Michael Lyons, the BBC Trust chairman, will make a statement on the inquiry's findings by the end of the week.
In a statement today, Thompson said it was "not appropriate for either Russell Brand or Jonathan Ross to continue broadcasting on the BBC until I have seen the full report of the actions of all concerned".
"This gross lapse of taste by the performers and the production team has angered licence payers," the director general added.
"I am determined that we satisfy them that any lessons will be learnt and appropriate action taken."
Brand, who is thought to be paid more than £200,000 a year, was preparing to fly to the US for "work reasons".
His other media employers, Channel 4 and the Guardian, said they would stand by him.
Channel 4 said Brand's new show Ponderland would air as planned on Thursday night, while the Guardian said his Saturday sports column would continue.
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