Los Angeles - R Kelly has cancelled a number of public events following a "health emergency".
The 45-year-old singer was due to launch a book on Thursday in New York and appear on NBC's Today show and the Jimmy Fallon Show but has pulled out after suffering from problems relating to surgery he had on his vocal chords last year.
A representative for R Kelly told TMZ.com: "The book launch is postponed due to a health emergency that has sidelined Mr Kelly in Chicago. We sincerely apologise for any inconvenience this has caused.
"Initial indications are that he is suffering from complications from surgery he had last year to treat an abscess on his vocal chords. It is unclear how long Kelly may be sidelined."
In addition to his health issues, the R&B singer has also suffered a number of financial setbacks recently.
Earlier this month it was revealed he owed $5m in unpaid taxes dating back to 2005, and in 2011 he was also forced to sell his mansion in Chicago due to failure to keep up with mortgage payments.
Despite paying tax bills of $2.6m in 2008 and $1m in 2009, he still owes the US federal government more than $4.8m.