The inquiry into the Mayor of London's comment to a Jewish reporter as he left a party cost an estimated £50,000, the government has disclosed.
Mr Livingstone is fighting the ruling by the Adjudication Panel
Ken Livingstone was suspended from office one year after comparing the reporter to a concentration camp guard.
He is currently fighting the ruling by the Adjucation Panel for England, which followed an investigation by the Standards Board for England.
The mayor's own legal costs have been estimated at about £80,000.
An investigation by council watchdog the Standards Board for England began after a complaint from the Jewish Board of Deputies about a comment made by Mr Livingstone in February 2005.
A year later, the Adjudication Panel for England found against him and suspended him from office after he was found to have brought his office into disrepute. He is currently taking that ruling to judicial review.
He was annoyed that Evening Standard reporter Oliver Finegold approached him as he left a party to mark 20 years since Chris Smith came out as the first gay MP.
After asking the reporter if he was a "German war criminal", Mr Finegold told him he was Jewish, and was quite offended.
"Ah right, well you might be, but actually you are just like a concentration camp guard, you are just doing it because you are paid to, aren't you?," said the mayor.
Mr Livingstone has claimed he was being harrassed and snapped after decades of abusive coverage from Associated Newspapers - publishers of the Evening Standard.
He has condemned his suspension as an "attack on the democratic rights of Londoners".