and sent to the United States for further tests yesterday.

Mr. Richardson went to hospital because he felt unwell, said Deputy Cabinet Secretary Mr. Leo Mills. He said he would not provide further details, to protect Mr. Richardson's privacy.

Tests in the US are expected to take several days.

Mr. Richardson survived a dangerous operation to remove a brain tumour in 1988. He had one kidney removed in 1990 after another tumour was discovered during a routine medical test.