"Mr Ted Turner deeply regrets offending the Polish people during a speech he made in Washington D.C., last week," a statement released by his office in Atlanta said.

"He has great respect for Poland and its people and extends his heartfelt apologies to them."

Deputy Polish Foreign Minister Radek Sikorski had described the joke as racist and demanded Mr Turner, vice-chairman of Time Warner, apologise or he would suffer financially.

Mr Turner made his joke during a speech to the National Family Planning and Reproductive Association in Washington.

When a member of the audience asked him what he would say if he ever met the Pope, himself a Pole, Mr Turner said: "Ever seen a Polish mine-detector?" and pointed at his foot.

Jokes casting doubt on the intelligence of Poles are common in certain parts of the United States.

"Regret" not enough

"This is racism and bigotry. Would Turner make the same sort of joke about other minorities, such as blacks, homosexuals or Jews?" asked the Polish deputy foreign minister.

Mr Turner, the founder of CNN television, sent an apology to the Polish Foreign Ministry in which he regretted any offence his comments had caused, but the government was not satisfied.

"If Turner believes the Poles are yokels maybe he can do without Polish taxpayer's money," Mr Sikorski had said.

He described the joke as an insult to Polish war veterans and said that if a fuller apology did not arrive within a week, Poland would consider breaking lucrative contracts with Time Warner.

This was not the first time the media mogul has got into trouble for making controversial comments.