Sepp Blatter has been admitted to hospital and is likely to remain there for several days.
The BBC reports the suspended Fifa president suffered what has been described as "a small breakdown" and "nervous shock", but is expected to make a full recovery.
A spokesman said Mr Blatter told him: "My brain and heart are fine, but my body is letting me down."
Mr Blatter, 79, was provisionally suspended for 90 days last month amid a corruption scandal.
The criminal case centres on whether he misused Fifa money by making a 2m euro (£1.35m) payment to Uefa president Michel Platini for consultation work. They both deny any wrongdoing.
A statement issued by Mr Blatter's lawyers said he was "disappointed" the ethics committee had not followed its own code in allowing him an opportunity to be heard.
They claimed the suspension was based on "a misunderstanding of the actions of the attorney general in Switzerland."
Seven candidates will stand to succeed Mr Blatter in Fifa's presidential election on 26 February.
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