LONDON (AFP) - Stephen Hawking, the acclaimed wheelchair-bound British scientist, is reported "comfortable" in hospital the day after being rushed there, a Cambridge University spokesman said on Tuesday.

Hawking, 67, whose book "A Brief History Of Time" became an international best-seller, spent the night in Addenbrooke's hospital in Cambridge, eastern England, being treated for a respiratory infection.

Cambridge University, where Hawking has been Lucasian professor of mathematics since 1979, said: "Professor Hawking is being kept in for observation at Addenbrooke's hospital this morning.

"He is comfortable and his family is looking forward to him making a full recovery."

He fell ill after flying back from a visit to the United States over the weekend, the spokesman said.

Hawking has achieved worldwide fame for his research, writing and television documentaries despite suffering since the age of 21 from motor neurone disease that has left him disabled and dependent on a voice synthesizer to communicate.