Disgraced ex-International Monetary Fund (IMF) head Dominique Strauss-Kahn suspected a smartphone that disappeared just before his arrest on sexual assault charges in New York was hacked, sources said Saturday, AFP reports.

Several sources close to Strauss-Kahn said that he called his wife, Anne Sinclair, as he was on his way to the airport to return to France to tell her "something serious" had happened.

Strauss-Kahn, who was taken off the plane May 14 following a complaint by a hotel maid that he attacked her, was referring to the loss of his official IMF BlackBerry phone and his suspicions that it might have been hacked, the sources said.

An article to be published in the New York Review of Books quotes unnamed sources close to Strauss-Kahn as saying that he was warned in a text message on the day of his arrest that an email he sent to his wife from the BlackBerry was read in the offices of French president Nicolas Sarkozy's UMP party in Paris.

The article raises questions that Strauss-Kahn, seen as the biggest threat to Sarkozy in next year's French presidential elections, may have been set up in order to discredit him.

Assault charges were dropped against him after prosecutors said that the maid, Nafissatou Diallo, lied about details of her allegations, although evidence showed that some sort of hurried sexual encounter did occur.

As a result of the scandal, Strauss-Kahn resigned as head of the IMF, his high-flying political career was left in tatters and since returning home, he has faced new allegations of sexual misconduct in France.

UMP secretary-general Jean-Francois Cope dismissed Saturday the idea of a plot against Strauss-Kahn as "absolutely ridiculous," alleging that it was cooked up to dent Sarkozy's chances of winning the election.

"I would like to see the evidence if it exists," he said on France's TF1 television.