West Yorkshire Police received more than 300 complaints about a speech earlier this month in Leeds in which he said Israelis were not welcome in the city where he has a constituency.
As reported in later editions of yesterday's Evening Times, detectives travelled to London to speak to him.
He spoke voluntarily, and is understood to have denied being anti-Semitic.
Mr Galloway said: "This is an absolute and despicable attempt to curb my freedom of speech by people who appear to be quite happy about the indiscriminate murder of Palestinians in Gaza.
"I won't be silenced, I will keep speaking out."
He is understood to believe no prosecution for inciting racial hatred will follow his comments. He is thought to have told police that Israel was not a race.
The Crown Prosecution Service will decide whether any charges should be made
District commander for Leeds Chief Superintendent Paul Money said: "A 59-year-old man has been interviewed under caution voluntarily following complaintsabout the content of a speech in Leeds earlier this month."