Former children's laureate Michael Rosen is "very poorly" after spending a night in intensive care, according to his family.
The statement posted on his Twitter page said he was "stable" and "alert" having been moved to a ward on Sunday.
Rosen, 73, is known for works including We're Going On A Bear Hunt, Little Rabbit Foo Foo and Chocolate Cake, and was children's laureate between 2007 and 2009.
From Michael's family: Michael is very poorly at the moment. Having spent a night in ICU, he is now doing "ok, stable, alert" and was able to go to a ward yesterday. Thank you very much for all your kind concern. Emma x @underthecranes@J0e_R0sen
— Michael Rosen (@MichaelRosenYes) March 30, 2020
It is not clear whether his condition is related to coronavirus.
The statement said: "Michael is very poorly at the moment. Having spent a night in ICU, he is now doing "ok, stable, alert" and was able to go to a ward yesterday."
Rosen's family thanked his Twitter followers "for all their kind concern".
Cressida Cowell, author of the How To Train Your Dragon series, wished him a swift recovery.
— Cressida Cowell (@CressidaCowell) March 30, 2020
She said on Twitter: "Willing with all my heart that @MichaelRosen will recover swiftly, he is such a wonderful man and does so much for children's books and for literacy."
Rosen's representatives have been contacted for comment.