Cardiff owner Vincent Tan has criticised Wigan chairman Dave Whelan and the club's new manager Malky Mackay, telling the BBC: "This is a racist chairman hiring a racist manager."
Malaysian businessman Tan reacted angrily to Whelan's comments about Jewish and Chinese people in a newspaper interview where he was defending his decision to hire former Cardiff boss Mackay.
The Football Association has also said its investigation into Whelan's comments will be treated "as a priority". It has written to the 77-year-old giving him three days to respond.
Whelan is facing the prospect of an FA charge after he responded to the controversy over Wigan's appointment of Mackay by telling the Guardian: "I think Jewish people do chase money more than everybody else."
Whelan also told the Guardian he did not view the word "chink" as offensive.
Whelan has apologised for any offence caused and denied being racist, but Tan said: "I think he insulted the dignity of all Jewish people. I think he insulted the dignity of Chinese."
The FA said in a statement: "We are very concerned to read about the comments that have been attributed to Dave Whelan. We take all forms of discrimination seriously.
"As with all such cases, this will be dealt with as a priority. The investigation is already under way and the FA's governance division have written to Mr Whelan. He has three working days to respond."
Mackay, who has also denied being racist, is himself the subject of an FA investigation for sending allegedly racist text messages to Iain Moody, his former head of recruitment at Cardiff. He was sacked by the Welsh club earlier this year.