A T-shirt company has issued an apology for advertising tops with slogans such as "Keep Calm and Rape A Lot" and "Keep Calm and Kill Her", with its founder saying yesterday the firm may go under.

Solid Gold Bomb said the offensive lines were created via an automated computer process which relied on online dictionaries to create the versions of the slogans based on the British second world war motto "Keep Calm and Carry On".

"I apologise for the offensive response this has created across the world," Solid Gold Bomb's Australian founder Michael Fowler said on the firm's website after the shirts advertised on Amazon unleashed outrage.

"No words can express how I feel about what has occurred and in no way do I condone or promote this serious issue."

Fowler said Amazon was his firm's main distribution channel and since the scandal broke sales had dropped from as many as 1,700 orders per day to as low as three in a single day.

Fowler said he had never intended to create offensive T-shirts, but he took responsibility for the fiasco.