Despite the national criticism the former liberal leader got a rousing send-off from his home town.

Dozens of supporters waved yellow balloons, the colour he used for his 2002 presidential election, threw yellow flowers and shouted "Cheer up!" as the bus rolled out of the small town.

Security was tight as the convoy -- a bus provided by the presidential office, presidential security vans and police vehicles -- headed for Seoul.

Local police deployed at highway stops and hundreds of riot police took station in and around the Seoul prosecutors' office.

Around 100 conservative critics outside the office demanded Roh's arrest while some 40 supporters waved yellow balloons.

Roh will be questioned about a payment worth one million dollars to his wife from a wealthy shoemaker, and a payment by the same man worth five million dollars to the husband of one of Roh's nieces, Yeon Cheol-Ho.

The questioning will also focus on whether the former head of state was aware of the embezzling of 1.25 billion won (US$930,000) by a former close aide, Jung Sang-Moon.

Prosecutors say the five million eventually ended up in the hands of Roh's son Gun-Ho. They have already arrested the shoemaker, Park Yeon-Cha, and Jung for alleged bribery.

Roh's wife and son as well as the husband of the niece have been questioned.

Roh has admitted his wife took an unspecified sum as a loan to pay off debts but denied he had been aware of it in advance. Gun-Ho and Yeon have said the five million dollars was a legitimate business investment.

The ex-president had apologised before as the scandal unfolded but has not admitted any personal wrongdoing.